Phys.org October 22, 2024 The photovoltaic effect can occur without metal/semiconductor or semiconductor/semiconductor interfaces in materials with spontaneous electric polarization due to a lack of spatial inversion symmetry known as bulk photovoltaic (BPV) effect which facilitates photoelectric conversion. Researchers in Japan reported an experimental demonstration of the BPV effect in α-In2Se3 films along the out-of-plane direction by using graphite films as transparent electrodes. A short-circuit current was detected under white light irradiation, and the sign was inverted upon inverting the direction of electric polarization, thus suggesting its origin to be the shift current, distinct from the effect occurring at the […]
Category Archives: Renewable energy
Caltech Demonstrates Space Based Solar
Next Big Future June 6, 2023 Researchers at Caltech launched Space Solar Power Project (SSPD) launched into orbit a prototype to beam power to Earth and that transmitted power from orbit to another receiver in orbit. They confirmed that MAPLE (Microwave Array for Power-transfer Low-orbit Experiment) can transmit power successfully to receivers in space. They programed the array to direct its energy toward Earth. It could survive the trip to space and operate there. Microwave Array for Power-transfer Low-orbit Experiment (MAPLE) and one of the three key experiments within SSPD-1 includes a small window through which the array can beam […]
Engineers harvest abundant clean energy from thin air, 24/7
Science Daily May 24, 2023 Previously described technologies for harvesting energy from air humidity are either not continuous or require unique material synthesis or processing, which has stymied scalability and broad deployment. Researchers at UMass developed a generic effect for continuous energy harvesting from air humidity which could be applied to a broad range of inorganic, organic, and biological materials. The materials were engineered with appropriate nanopores to allow air water to pass through and undergo dynamic adsorption–desorption exchange at the porous interface, resulting in surface charging. The top exposed interface experienced the dynamic interaction more than the bottom sealed […]
Newly developed hydrogel nanocomposite for the mass production of hydrogen
Phys.org April 27, 2023 Despite recent progress in designing highly active photocatalysts, inefficient solar energy and mass transfer, the instability of catalysts and reverse reactions impede their practical large-scale applications. Storing solar energy in chemical bonds aided by heterogeneous photocatalysis is desirable for sustainable energy conversion. Researchers in South Korea designed a floatable photocatalytic platform constructed from porous elastomer–hydrogel nanocomposites. The nanocomposites at the air–water interface featured efficient light delivery, facile supply of water and instantaneous gas separation. Consequently, a high hydrogen evolution rate of 163 mmol h–1 m–2 was achieved using Pt/TiO2 cryoaerogel, even without forced convection. When fabricated in an area […]
Photosynthesis ‘hack’ could lead to new ways of generating renewable energy
Science Daily March 22, 2023 Previous approaches to ‘re-wire’ photosynthesis for higher biomass-conversion efficiencies and new reaction pathways have focused on charge extraction at terminal electron acceptors of the photosystems. Electron extraction at earlier steps, perhaps immediately from photoexcited reaction centres, would enable greater thermodynamic gains. Using in vivo ultrafast transient absorption (TA) spectroscopy an international team of researchers (UK, Finland, Germany) demonstrated the extraction of electrons directly from photoexcited PSI and PSII at early points (several picoseconds post-photo-excitation) with live cyanobacterial cells or isolated photosystems, and exogenous electron mediators. They postulated that these mediators oxidize peripheral chlorophyll pigments participating […]
A step towards solar fuels out of thin air
Science Daily January 4, 2023 Taking inspiration from the way plants can convert sunlight into chemical energy using carbon dioxide from the air, researchers in Switzerland have invented a solar-powered artificial leaf, built on a novel electrode capable of harvesting water from the air for conversion into hydrogen fuel. The system combines semiconductor-based technology and the electrodes that are porous and transparent. When the device was simply exposed to sunlight, it took water from the air and produced hydrogen gas. The coating of various semiconductors on the substrates was established including Fe2O3 (chemical bath deposition), CuSCN and Cu2O (electrodeposition), and […]
New technology can help combat climate crisis
Science Daily August 3, 2022 Researchers in the UK developed a chemical process that converts sunlight, water and carbon dioxide into acetate and oxygen to produce high-value fuels and chemicals powered by renewable energy. As part of the process, they grew CO2-fixing acetogenic bacterium Sporomusa ovata on a scalable and cost-effective photocatalyst sheet consisting of a pair of particulate semiconductors. The system effectively produces acetate and oxygen using only sunlight, CO2 and H2O, achieving a solar-to-acetate conversion efficiency of 0.7% at ambient conditions (298 K, 1 atm). The photocatalyst sheet oxidizes water to O2 and provides electrons and hydrogen to S. ovata […]
Bacteria for blastoff: Using microbes to make supercharged new rocket fuel
Science Daily June 30, 2022 An international team of researchers (Denmark, USA – Lawrence Berkely National Laboratory, Sandia National Laboratory, Pacific Northwest National Laboratory, UC Berkeley) explored the chemical diversity encoded in thousands of bacterial genomes to identify and repurpose naturally occurring cyclopropanated molecules. They identified a set of candidate iterative polyketide synthases (iPKSs) predicted to produce polycyclopropanated fatty acids (POP-FAs), expressed them in Streptomyces coelicolor, and produced POP-FAs. By determining the structure of the molecules, they were able increase their production 22-fold and produce polycyclopropanated fatty acid methyl esters (POP-FAMEs). Their research showed that the POP-FAMEs and other POPs […]
Japan Is Dropping a Gargantuan Turbine Into The Ocean to Harness ‘Limitless’ Energy
Science Alert June 10, 2022 To tap into the source of power beneath the waves an industry in Japan has constructed a 330-ton prototype of a device called Kairyu whose structure consists of a 20 meter (66 foot) long fuselage flanked by a pair of similar-sized cylinders, each housing a power generation system attached to an 11-meter-long turbine blade. When tethered to the ocean floor by an anchor line and power cables, the device can orient itself to find the most efficient position to generate power from the push of a deep-water current, and channel it into a grid. Kairyu […]
Towards sustainable, self-powered energy devices with coconuts
Nanowerk April 25, 2022 An international team of researchers (North Korea, Australia, India) has demonstrated both energy harvesting and storage devices such as piezoelectric nanogenerator (PNG) and piezo supercapacitor (PSC) by enforcing coconut husk (CH) as a filler into the polymer separator. The CH powder was immobilized into the polyvinyl difluoride (PVDF) matrix to improve its piezoelectric performance. The poled PNG with a 7 wt% of CH powder/ PVDF composition delivered an output of 14 V, 50 nA current, and a power density of 0.35 μW/cm2 at 100 MΩ. The output is enough to charge commercial capacitors and power electronic […]