Phys.org January 31, 2022 Bismuth vanadate (BiVO4) has been widely investigated as a photocatalyst or photoanode for solar water splitting, but its activity is hindered by inefficient cocatalysts and limited understanding of the underlying mechanism. An international team of researchers (China, Japan) demonstrated significantly enhanced water oxidation on the particulate BiVO4 photocatalyst via in situ facet-selective photodeposition of dual-cocatalysts that exist separately as metallic Ir nanoparticles and nanocomposite of FeOOH and CoOOH (denoted as FeCoOx), as revealed by advanced techniques. The mechanism of water oxidation promoted by the dual-cocatalysts is experimentally and theoretically unraveled, and mainly ascribed to the synergistic […]
Tag Archives: Renewable energy
Making clean hydrogen is hard, but researchers just solved a major hurdle
Phys.org July 19, 2021 To create electrically conductive paths through a thick silicon dioxide researchers at UT Austin used a technique first deployed in the manufacturing of semiconductor electronic chips. By coating the silicon dioxide layer with a thin film of aluminum and heating the entire structure, arrays of nanoscale “spikes” of aluminum that completely bridge the silicon dioxide layer were created. These can be replaced by nickel or other materials that help catalyze the water-splitting reactions. When illuminated by sunlight, the devices efficiently oxidized water to form oxygen molecules while also generating hydrogen at a separate electrode and exhibited […]
Scientists home in on recipe for entirely renewable energy
EurekAlert July 7, 2021 Researchers in Ireland have developed a technique that would enable the future production of entirely renewable, clean energy from which water would be the only waste product. They used an automated combinatorial approach and advanced quantum chemical modelling and found nine earth-abundant combinations of metals and ligands as highly promising leads for experimental investigation. They found chromium, manganese, iron to be especially promising. Thousands of catalysts based around these key components can now be placed in a melting pot and assessed for their abilities as the hunt for the magic combination continues. They have screened 444 and […]
Carbon-neutral ‘biofuel’ from lakes
Science Daily March 31, 2021 Although the greenhouse gas methane is less well known and much rarer in the atmosphere, its global warming potential is 80 to 100 times greater per unit. Methane from lakes and water reservoirs makes up about 20% of global natural methane missions. Researchers in Switzerland outline the potential and theoretical possibilities for using methane from lakes and other freshwater bodies for sustainable energy production. The feasibility of up-scaled adsorption-driven technologies to capture and refine aqueous Biogenic CH4 is mostly generated from biomass produced through atmospheric CO2 uptake. Its exploitation in freshwaters can thus secure large […]
New green technology generates electricity ‘out of thin air’
Phys.org February 17, 2020 Researchers at UMass Amherst have developed a thin-film device they call “Air-gen”, made from nanometre-scale protein wires harvested from the microbe Geobacter sulfurreducens that can generate continuous electric power in the ambient environment. The devices produce a sustained voltage of around 0.5 volts across a 7-micrometre-thick film, with a current density of around 17 microamperes per square centimetre. According to the researchers the driving force behind this energy generation is a self-maintained moisture gradient that forms within the film when the film is exposed to the humidity that is naturally present in air. Connecting several devices […]
Mystery of negative capacitance in perovskite solar cells solved
Eurekalert April 5, 2019 An international team of researchers (Switzerland, Iran) found that the large perovskite capacitances are not classical capacitances in the sense of charge storage, but just appear as capacitances because of the cells’ slow response time. They found that the origin of the apparent capacitance is a slow modification of the current passing the contact of the solar cells, which is regulated by a slow accumulation of mobile ionic charge. A slowly increasing current appears like a negative capacitance in the impedance spectra. The work sheds light on the interaction between the photovoltaic effect in these devices […]
Wave device could deliver clean energy to thousands of homes
Science Daily February 12, 2019 An international team of researchers (Italy, UK) developed a device, known as a Dielectric Elastomer Generator (DEG), using flexible rubber membranes. It is designed to fit on top of a vertical tube which, when placed in the sea, partially fills with water that rises and falls with wave motion. As waves pass the tube, the water inside pushes trapped air above to inflate and deflate the generator on top of the device. As the membrane inflates, a voltage is generated. This increases as the membrane deflates, and electricity is produced. In a commercial device, this […]
New, highly stable catalyst may help turn water into fuel
Science Daily September 28, 2018 Much of the previous work was performed with electrolyzers made from just two elements — one metal and oxygen. A team of researchers in the US (University of Illinois, Argonne National Laboratory) developed a porous material — a pyrochlore oxide of yttrium ruthenate which was more porous and had a new crystalline structure. As a porous structure is highly desirable when it comes electrocatalysts, the new materials could split water molecules at a higher rate than the current industry standard…read more. TECHNICAL ARTICLE
Dual-layer solar cell sets record for efficiently generating power
Nanowerk August 31, 2018 The combination of hybrid perovskite and Cu(In,Ga)Se2 (CIGS) has the potential for realizing high-efficiency thin-film tandem solar cells because of the complementary tunable bandgaps and excellent photovoltaic properties of these materials. Researchers in Japan used nanoscale interface engineering of the CIGS surface and a heavily doped poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) hole transport layer between the subcells that preserves open-circuit voltage and enhances both the fill factor and short-circuit current. The solar cell achieved a 22.43% efficiency, and unencapsulated devices under ambient conditions maintained 88% of their initial efficiency after 500 hours of aging under continuous 1-sun illumination… read […]