Year 10, issue 1. February 3rd, 2023.

Featured paper A team of researchers from six Brazilian institutions increased by around 30 times the photocatalytic activity of a semiconductor that is used in the generation of green hydrogen. The work was reported at ACS Applied Energy Materials. Know more. If you are the author of high-quality scientific work, carried out wholly or mostly in Brazil and published in a journal with a high impact factor, and you want to publicize it in our community, contact us to have your paper considered in the monthly selection of the “Featured paper”: comunicacao@sbpmat.org.br. XXI B-MRS Meeting Maceió (AL), October 1st to 5th, 2023 Symposia. The event comprises 24 thematic symposia covering design, synthesis, characterization, processing and applications of various materials, from traditional alloys to bio-based polymers. More than 100 researchers from Brazil, Argentina, Australia, Austria, Belgium, Canada, Chile, Colombia, France, Germany, Italy, Portugal, Switzerland, UK and USA are organizing our symposia. See the list of symposia and their description. Submissions. Abstract submission within the symposia is open until April 17th. Know more. Student awards. Contributions submitted by students and approved for presentation will be able to apply for student awards until July 17. Know more. Registrations. Registration is open, with special fees for students and researchers from institutions from Latin American countries. See the values. Venue. The venue for the event will be the Ruth Cardoso Cultural and Exhibition Center, in the city of Maceió, the capital of Alagoas state. Know more. Chairmen. The general coordinators of the event are professors of the Brazilian Federal University of Alagoas (UFAL) and research productivity fellows: Carlos Jacinto da Silva, from the Institute of Physics, and Mario Roberto Meneghetti, from the Institute of Chemistry and Biotechnology. Visit the event website! Manifestos – B-MRS repudiated the attacks on democracy and the rule of law that took place in Brasília on January 8, with the invasion by terrorists of the headquarters of the three powers of the Republic. Opportunities – Applications for the Erasmus Mundus Masters in Materials Science and Engineering AMASE are open. AMASE is a joint program of universities in Germany, France, Spain, Italy, Austria and Sweden. There are scholarships for the best students. Know more. Upcoming events – II Encuentro de Investigadores en Ciencia de Materiales. Montevideo (Uruguay). April 20 and 21, 2023. Website. – 49ª International Conference on Metallurgical Coatings and Thin Films (ICMCTF). San Diego (USA). May 21 to 26, 2023. Website. – 41st International Conference on Vacuum Ultraviolet and X-ray Physics (VUVX 2023). Campinas (SP, Brazil). July 3 to 7, 2023. Website. – IV Brazilian Nanocellulose Summit. São Carlos (SP, Brazil). August 9th to 11th, 2023. Website. – XXI B-MRS Meeting. Maceió (AL, Brazil). October 1 to 5, 2023. Website. – 4th International Brazilian Conference on Tribology (TriboBR). Victoria (ES, Brazil). November 26th to 30th, 2023. Website. Follow us on social networks

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A team of scientists from Brazilian institutions has increased by about 30 times the capacity of a semiconductor material to produce hydrogen by means of water photolysis, a process that consists of dividing the water molecule using light as the only source of energy. The advance contributes to the development of efficient ways to generate green hydrogen, which is the fuel produced using renewable and clean energy.

For photolysis to take place, it is necessary to have photocatalysts suspended in water. A photocatalyst is a semiconductor capable of absorbing light and, from there, generating the charges (electrons and holes) that are necessary to dissociate water molecules (H2O) into hydrogen (H2) and oxygen (O2) though oxidation and reduction reactions. Furthermore, the material must be stable in an aqueous environment.

 

“Strontium titanate (SrTiO3) is one of the main semiconductor materials applied to photolysis for the production of green hydrogen, as it meets the physicochemical requirements for oxidizing and reducing the water molecule,” says Professor Renato Vitalino Gonçalves (IFSC-USP) , corresponding author of the article that reports this research in ACS Applied Energy Materials. “However, this material has some intrinsic characteristics that limit its photocatalytic potential, such as, for example, its wide bandgap of ~3.2 eV, which restricts its optical absorption to the UV region, which corresponds to only 4% of the solar spectrum”, completes the scientist. Another limitation of this material, common to all semiconductors, is the rapid recombination of electrons and holes, which prevents these charges from flowing freely and promoting oxidation and reduction reactions.

Thus, the Brazilian team, led by Professor Gonçalves, decided to modify strontium titanate to increase its efficiency in photolysis. Initially, the researchers doped the semiconductor with the transition metal molybdenum (Mo) and obtained disaggregated cubic particles with well-defined faces. The unconventional dopant was responsible for making the material capable of absorbing light in the visible region, which represents around 43% of the solar spectrum.

In a second moment, the authors of the work deposited nickel nanoparticles of around 2 nm on the surface of the particles. The result was a junction of two types of semiconductors: Mo:SrTiO3, n-type, and NiO@Ni(OH)2, p-type. “In this new configuration, the photogenerated holes are directed to the NiO@Ni(OH)2 structure, while the electrons migrate to the Mo:SrTiO3 surface, resulting in better charge separation and, consequently, a reduction in the recombination rate of electrons and holes”, explains Gonçalves.

 

The photocatalysts were placed in suspension in an aqueous solution with 20% methanol as a sacrificial agent – a widely used strategy to increase hydrogen production and also generate high-value by-products for the chemical industry. “When mixed with water, which oxidation is slow, this alcohol is preferentially oxidized”, says Professor Gonçalves. “Even though, the H2 is produced from the reduction of the water molecule and not as a by-product of methanol oxidation”, he adds.

By increasing the absorption of light and decreasing the loss of photogenerated charges, the enhanced material presented an excellent result in the production of hydrogen by photolysis: an increase of its photocatalytic activity of about 30 times compared with the pure semiconductor.

Brazilian scientific cooperation

This scientific work was led by Professor Renato Vitalino Gonçalves, who coordinates the Nanomaterials and Advanced Ceramics Group (NaCA) and the Artificial Photosynthesis and Nanomaterials Laboratory (LAPNano) at IFSC-USP. The synthesis of materials and the study of their structural, optical and electronic properties, as well as their photocatalytic performance for the production of green hydrogen were developed at IFSC-USP, within the doctoral research of Higor Andrade Centurion, supervised by Professor Gonçalves.

The identification and characterization of the nickel nanoparticles in the material was carried out in collaboration with a team from UFABC and LNNano-CNPEM, formed by Professor Flávio Leandro de Souza, postdoctoral student Ingrid Rodriguez-Gutierrez and researcher Jefferson Bettini. In collaboration with Professor Liane M. Rossi (IQ-USP), nickel was quantified using the flame atomic absorption spectroscopy technique.

In addition, with the collaboration of Professor Heberton Wender (UFMS) it was possible to carry out photoluminescence measurements that corroborated the suppression of recombination of charges photogenerated by the formation of the p – n junction.

Finally, computer simulations that made it possible to understand the behavior of the materials were carried out with Professor Matheus M. Ferrer, from UFPel, and Master’s student Lucas Gabriel Rabelo, from IFSC-USP, who also received guidance from Professor Gonçalves.

The work was funded mainly by the São Paulo research foundation (FAPESP) and, through the RCGI, by FAPESP/Shell. It also had financial support from the research foundation of Rio Grande do Sul (FAPERGS).

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Paper reference: Constructing Particulate p−n Heterojunction Mo:SrTiO3/NiO@Ni(OH)2 for Enhanced H2 Evolution under Simulated Solar Light. Higor A. Centurion, Lucas G. Rabelo, Ingrid Rodriguez-Gutierrez, Mateus M. Ferrer, Jefferson Bettini, Heberton Wender, Liane M. Rossi, Flavio L. Souza, and Renato V. Gonçalves. ACS Appl. Energy Mater. 2022, 5, 12727−12738. https://doi.org/10.1021/acsaem.2c02337.

Corresponding author contact: rgoncalves@ifsc.usp.br.

Brazilian Materials Research Society (B-MRS) declares its total rejection of the serious aggression against democracy and the rule of law in our country, which took place yesterday in Brasília, with the invasion by terrorists of the headquarters of the three powers of the Republic.

B-MRS stands in solidarity with the Brazilian executive,, judiciary and legislative bodies in defense of the Federal Constitution, its values and principles.

It is essential to verify the facts and punish those responsible for terrorist acts, without amnesty, and with ‘Democracy forever’!

B-MRS Executive Board

 

To view in browser, click here. Year 9, issue 11. December 22nd, 2022.

End-of-year message In 2022, we returned to the ‘new normal’ with in-person activities interspersed with virtual ones and masks disappearing from our daily lives thanks to the vaccination of most of the population against Covid-19. That is why we were able to meet again at our annual event in Foz do Iguaçu last September. The strength and resilience of our community were present at all times. Despite the lack of funding and difficult working conditions we had almost 1,200 participants and 22 partner companies present in Foz do Iguaçu! We hope that the celebratory cry of students at our traditional conference party can always be fulfilled: “Online event never again!”. In 2023, we want science to be heard and respected with the changes to come in Brazil. However, as a scientific society, we will continue to fight and act together with our peers and the community in defense of education as a pillar for a fairer society, and of science and technological development as tools to achieve decent living conditions for the entire population. An excellent end of the year to all! May we recharge our energies to overcome the many challenges ahead, hoping for a better country and a better world. B-MRS Executive Board XXI B-MRS Meeting Maceió (Alagoas state, Brazil), October 1 to 5, 2023 Symposia call. 35 proposals were submitted by the community! In early 2023 we will release the final list of approved symposia. Venue. The venue for the event will be the Ruth Cardoso Cultural and Exhibition Center, in the city of Maceió. Know more. Chairmen. The general coordinators of the event are two professors from the Brazilian Federal University of Alagoas (UFAL) and research productivity fellows: Carlos Jacinto da Silva, from the Institute of Physics, and Mario Roberto Meneghetti, from the Institute of Chemistry and Biotechnology. Visit the event website! Events – II Encuentro de Investigadores en Ciencia de Materiales. Montevideo (Uruguay). April 20 and 21, 2023. Website. – 41st International Conference on Vacuum Ultraviolet and X-ray Physics (VUVX 2023). Campinas (Brazil). July 3 to 7, 2023. Website. – XXI B-MRS Meeting. Maceio (Brazil). October 1st to 5th, 2023. Website. – 4th International Brazilian Conference on Tribology (TriboBR). Vitória (Brazil). November 26th to 30th, 2023. Website. Follow us on social networks

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In 2022, we returned to the ‘new normal’ with in-person activities interspersed with virtual ones and masks disappearing from our daily lives thanks to the vaccination of most of the population against Covid-19.

That is why we were able to meet again at our annual event in Foz do Iguaçu last September. The strength and resilience of our community were present at all times. Despite the lack of funding and difficult working conditions we had almost 1,200 participants and 22 partner companies present in Foz do Iguaçu!

We hope that the celebratory cry of students at our traditional conference party can always be fulfilled: “Online event never again!”. In 2023, we want science to be heard and respected, with the changes to come in the country. However, as a scientific society, we will continue to fight and act together with our peers and the community in defense of education as a pillar for a fairer society, and of science and technological development as tools to achieve decent living conditions for the entire population.

An excellent end of the year to all! May we recharge our energies to overcome the many challenges ahead, hoping for a better country and a better world.

B-MRS Executive Board

 

Year 9, issue 10. December 9th, 2022.

Featured paper Brazilian researchers prepared black titanium dioxide using a simple and scalable method and used this low-cost photosensitive nanomaterial as a photoanode in a fuel cell. The device was able to generate electricity, with very high efficiency, using organic compounds as fuel and sunlight as the energy source. The work was reported in ACS Applied Materials & Interfaces. Know more. If you are the author of high-quality scientific work, carried out wholly or mostly in Brazil and published in a journal with a high impact factor, and you want to publicize it in our community, contact us to have your paper considered in the monthly selection of the “Featured paper”: comunicacao@sbpmat.org.br. XXI B-MRS Meeting Maceió (Alagoas state, Brazil), October 1st to 5th, 2023 Call for symposia. Groups of researchers who want to organize a symposium on their research topic within the next B-MRS Meeting can submit a proposal by filling in a simple form. The call ends this Saturday, December 10th. Access the symposium submission form. Venue. The venue for the event will be the Ruth Cardoso Cultural and Exhibition Center, in the city of Maceió. Know more. Chairmen. The general coordinators of the event are two professors from the Brazilian Federal University of Alagoas (UFAL) and research productivity fellows: Carlos Jacinto da Silva, from the Institute of Physics, and Mario Roberto Meneghetti, from the Institute of Chemistry and Biotechnology. Visit the event website! Members Prof. Sergio Machado Rezende (UFPE), a founding member of B-MRS, is part of the science and technology team of the government transition. The group was tasked with carrying out a diagnosis of the area and proposing measures. Rezende was the Brazilian Minister of S&T (2005 – 2010), among other management positions, and has world-class production in Physics of Materials. Prof. Edvani Curti Muniz (UTFPR, UFPI and UEM) is the new coordinator of the Materials Area at CAPES, the Brazilian federal agency in charge of the quality of graduate programs. His name was one of the five sent to CAPES by B-MRS in September of this year after consulting our members. Edvani has extensive experience in academic management positions and a solid scientific career. Prof. Ana Flávia Nogueira (UNICAMP), member of the B-MRS Council, was admitted as a fellow of the Royal Society of Chemistry and elected a permanent member of the Brazilian Academy of Sciences – two peer recognitions for her scientific career and leadership. She has important contributions in emerging materials for solar cells and she heads the Center for Innovation on New Energies, which has near 300 researchers. If you are a B-MRS member and want to share news about your professional activities in our community, please contact us: comunicacao@sbpmat.org.br. Papers from the community This work led by Prof. Helinando Pequeno de Oliveira (UNIVASF), a B-MRS member, describes the simple production of a low-cost flexible triboelectric nanogenerator based on PVA membranes with fibroin (material extracted from the silkworm). The device, which converts mechanical energy into electrical energy, is promising for use in wearable electronics. Go to the paper in Nano Energy: https://doi.org/10.1016/j.nanoen.2022.108035. This review article with authors of our Brazilian community was highlighted by ACS Sensors as one of the most read among those recently published. The text brings a review of the advances achieved in the last decade in amine sensors and points out ways to continue the development of these devices, which allow monitoring the quality of food and avoiding wastage. Access the article: https://doi.org/10.1021/acssensors.2c00639. If you are the author of an impactful paper in the Materials area and wish to share it with our community, please contact us: comunicacao@sbpmat.org.br. Manifestos – B-MRS repudiated a recent decree of the federal government, which prohibited financial disbursements in the month of December, preventing the payment of around 200,000 student and postdoc scholarships. The Society sympathized with the scholarship holders at this difficult time and demanded the immediate recomposition of the budget. Opportunities – Open until December 15: Call for proposals to carry out experiments on Sirius, the new Brazilian laboratory of synchrotron light. Researchers from Brazilian and foreign institutions in Latin American and Caribbean countries can also request financial assistance for travel and lodging in Campinas. Know more. – Opportunities for PhDs at the Center for Innovation on New Energies within a project on graphene and niobium oxide solar modules, to be carried out mainly at UNICAMP. Registration until December 16. Know more – Open until February 15: Applications for the Erasmus Mundus Masters in Materials Science and Engineering AMASE – a joint program of universities in Germany, France, Spain, Italy, Austria and Sweden, with scholarships for the best students. Know more. To follow the opportunities in the area, enter the B-MRS group on Linkedin. Upcoming events – 11th International Conference of the African Materials Research Society (AMRS2022 ). Dakar (Senegal). December 12th to 15th, 2022. Website. – Webinar (In-)visibility of women in science: historical perspectives. Online. December 16, 2022. Website. – II Encuentro de Investigadores en Ciencia de Materiales. Montevideo (Uruguay). April 20 and 21, 2023. Website. – 41st International Conference on Vacuum Ultraviolet and X-ray Physics (VUVX 2023). Campinas, (São Paulo). July 3 to 7, 2023. Website. Follow us on social media

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Researchers from the Brazilian Federal University of Mato Grosso do Sul (UFMS) have developed a photosensitive nanomaterial that is very efficient to produce electricity from organic compounds used as fuel and sunlight as the energy source. The process, which is relatively clean and inexpensive, is carried out in a device called a photo fuel cell. In the work, the team used methanol (CH3OH) as fuel, a liquid alcohol that stores a large amount of energy and, when used, generates much less carbon emissions than fossil fuels. The compound has gained attention as a fuel for clean energy generation, mainly because it can be produced from biomass.

“The photo fuel cell developed in our work contains a simple technology capable of converting methanol into energy using only solar energy as an external driving force, operating with simple, stable, abundant materials free of noble metals, which makes the cost of the process considerably low compared to conventional fuel cells”, says Professor Heberton Wender, a corresponding author of the article that reports this advance in the journal ACS Advanced Materials and Interfaces.

Fuel cells are devices that directly convert the chemical energy of a fuel into electrical energy through electrochemical reactions, with low or zero carbon emissions. Used for decades to supply energy in satellites and spacecraft, fuel cells are already present in homes, businesses, industries and electric cars, and are becoming increasingly relevant in the face of the need to generate energy in the cleanest way possible to mitigate climate change. However, the materials needed to efficiently catalyze electrochemical reactions in fuel cell electrodes are generally based on expensive and scarce elements such as noble metals. Therefore, several alternatives are being investigated; among them, the development of fuel photocells.

In these devices, inexpensive photosensitive materials based on abundant elements help drive reactions through the electrons and holes they generate when excited by sunlight. One such material is titanium dioxide (TiO2). This compound, which is usually in the form of a white powder, is not easily degraded by light and is simple to prepare. However, it has an important limitation: it only absorbs ultraviolet radiation, failing to take advantage of other wavelengths that are also present in sunlight, such as the so-called visible light.

In this context, the initial idea was born for the work of the UFMS team, which was developed within Luiz Felipe Plaça’s doctorate under the guidance of Prof. Heberton. “We thought of using self-doped titanium dioxide, that is, with self-induced structural defects, using a simple, inexpensive process that can be easily scaled up in the future”, says the researcher. “That was when we decided to use heat treatment in a reducing atmosphere with small amounts of sodium borohydride (NaBH4)”, he details. The idea generated great results. The treatment made it possible to control the density of defects in the titanium dioxide nanoparticles and, in this way, increase their ability to absorb radiation, including part of the visible spectrum of sunlight. Furthermore, the material lost its characteristic white color and turned black.

The black titanium dioxide was placed on a transparent conductive glass substrate and used as the photoanode of the fuel cell. The photoanode is the component responsible for absorbing sunlight and transforming it into electrons and holes that will reduce oxygen and oxidize fuel, respectively, generating the desired electric current at the end of the process. With the black titanium dioxide photoanodes, the efficiency of the fuel cell showed a very considerable increase in its ability to produce electric current from methanol and solar energy. “The improved device, without the use of noble metals, showed a 2,000% increase in maximum output power”, says Professor Heberton. “This represents an impressive efficiency and puts self-doped titanium dioxide on the list of the most promising materials to be used as photoanodes in photocells fueled by methanol or alternative fuels such as ethanol, glycerol, other alcohols and even organic pollutants with higher molar mass”.

As it can be supplied with organic pollutants – a possibility that was explored in other work by the team, the photocell could be used to decontaminate water without additional energy costs and even generate a little extra electricity for external use in low-power devices. “In a hypothetical scenario, it would be possible to purify water from effluents in rural properties while producing energy”, points out Professor Cauê Alves Martins, who is also a corresponding author of the ACS Applied Materials and Interfaces article.

In addition to the laboratory photocell, the authors prepared, with the new photoanode, a prototype of a small portable device: a microfluidic photo fuel cell. The device, which fits in the palm of a hand, can be produced in less than an hour at a cost of less than $2.00. To develop the prototype, the team had the participation of an undergraduate student in Physics Engineering  at UFMS, Pedro Lucas S. Vital, who, guided by Prof. Cauê, accepted the challenge of preparing the cell using a 3D printer. The device was also tested, with good results. Despite being a good prototype, the engineering of the device can yet be improved to increase the power density via scale out, with more devices operating together, comment Heberton and Cauê.

The work is the result of a well-established collaboration between two research groups at the UFMS Institute of Physics: Nano&Photon, coordinated by Professor Heberton Wender, and the Electrochemistry Research Group, led by Professor Cauê Alves Martins. Researchers from the Institute of Chemistry of São Carlos (IQSC-USP) also participated in the work.

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Paper reference: Black TiO2 Photoanodes for Direct Methanol Photo Fuel Cells. Luiz Felipe Plaça, Pedro-Lucas S. Vital, Luiz Eduardo Gomes, Antonio Carlos Roveda Jr., Daniel Rodrigues Cardoso, Cauê Alves Martins, and Heberton Wender. ACS Applied Materials & Interfaces. DOI: 10.1021/acsami.2c04802.

Corresponding authors contact: heberton.wender@ufms.br, caue.martins@ufms.br.

 

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In numbers More than 1,100 participants. 60% men, 40% women. 41.5% professionals, 42.5% graduate students, 11% undergraduate students and 5% exhibitors. 29 countries in America, Europe, Asia, Africa and Oceania. 23 Brazilian states, covering the 5 regions of the country. About 1,200 works effectively presented within 22 symposia: more than 340 oral presentations, 750 posters and 100 invited lectures. 27 students´contributions awarded. Up to 13 rooms in simultaneous sessions. 7 plenary lectures in addition to the memorial lecture. 3 technical lectures by exhibitors. 1 pre-event tutorial. 22 sponsors – exhibitors. Event report The traditional account of the event, with some files of the presentations and photos. Access the report here. List of awarded students The works and authors that received the awards from B-MRS, ACS and RSC for the best contributions presented by students at the event. Access the list and the photo album here. XXI B-MRS Meeting: call for symposium proposals The XXI B-MRS Meeting will be held in Maceió from October 1st to 5th, 2023, coordinated by UFAL professors Carlos Jacinto da Silva and Mário Roberto Meneghetti. The call for symposium proposals and the nomination of plenary speakers for the event are now open. Know more.   CERTIFICATES. The XX B-MRS Meeting participation and presentation certificates are available in the event system: https://www.eventweb.com.br/xxsbpmat/home-event/. EVENT PHOTOS. The main photos of the event (sessions, party, ceremonies, tributes), taken by the official photographer, for you to look at or download, organized by day, are available at Google Drive. Follow us on social media

The call for symposium proposals to compose the XXI B-MRS Meeting is open until December 3rd this year. The event will be held from October 1st to 5th, 2023 in Maceió (Alagoas, Brazil), chaired by Professors Carlos Jacinto da Silva and Mario Roberto Meneghetti, from the Federal University of Alagoas (UFAL).

Proposals can be submitted by teams of researchers (Ph.D.), preferably of international composition, wishing to organize a symposium within the event on a research topic in the field of Materials Science and Technology – from the design, synthesis and characterization of materials to their applications in the most diverse segments. The list of approved final symposia will be published on December 16 this year.

To submit a symposium proposal, simply fill out, in English, the online form available at http://sbpmat.org.br/proposed_symposium/ .

In addition, the event’s organizing committee invites the community to send suggestions of plenary speakers (internationally renowned scientists who can give a motivational lecture on advances made over time in a particular research topic, as well as the challenges and perspectives for the future). The plenary lectures should interest a wide audience, with different levels of training and thematic specialties.

Suggestions for the plenary lectures must be submitted by November 20th of this year through this Google form.

XXI B-MRS Meeting website: https://www.sbpmat.org.br/21encontro/ .