Phys.org August 13, 2024 Hydrogen production through anion-exchange membrane water electrolyzers (AEMWEs) offers cost advantages over proton-exchange membrane counterparts, mainly due to the good oxygen evolution reaction (OER) activity of platinum-group-metal-free catalysts in alkaline environments. However, the electrochemical oxidation of ionomers at the OER catalyst interface can decrease the local electrode pH, which limits AEMWE performance. Various strategies at the single-cell-level have been explored to address this issue. An international team of researchers (South Korea, USA – Los Alamos National Laboratory, University of North Carolina, Lawrence Berkeley National Laboratory) reviews the current understanding of electrochemical ionomer oxidation and strategies to […]
Category Archives: Hydrogen production
Energy-saving electrochemical hydrogen production via co-generative strategies in hybrid water electrolysis
Phys.org February 26. 2024 Coupling the kinetically favorable anodic electrooxidation reactions of easily oxidizable substances with the hydrogen evolution reaction in a hybrid water electrolysis (HWE) configuration solves the pollutant emission and biomass recycling problems and maximizes the return on energy profiteering. An international team of researchers (China, Egypt, Singapore) has provided an overview of HWE system, design, and engineering of high reactive/selective/stable electrodes/electrocatalysts for anodic oxidation of organic/biomass substrates. They provided possible reaction mechanisms from both experimental and theoretical perspectives to promote the efficiency of synergistic electrocatalysis. They reviewed, the recent research breakthroughs in the field of HWE technology […]
Novel nanocrystal harnesses full solar spectrum for hydrogen production
Nanowerk February 27, 2024 Near infrared energy remains untapped toward the maneuvering of entire solar spectrum harvesting for fulfilling the nuts and bolts of solar hydrogen production. An international team of researchers (Taiwan, Japan)used Au@Cu7S4 yolk@shell nanocrystals as dual-plasmonic photocatalysts to achieve remarkable hydrogen production under visible and near infrared illumination. Data revealed the prevalence of long-lived charge separation states for Au@Cu7S4 under both visible and near infrared excitation. Combined with the advantageous features of yolk@shell nanostructures, Au@Cu7S4 achieved a peak quantum yield of 9.4%. The design of a sustainable visible- and near infrared-responsive photocatalytic system is expected to inspire […]
New noble-metal-free electrocatalyst decreases the energy required to generate hydrogen gas from water
Phys.org October 19, 2023 Generating hydrogen gas from clean sources, such as the splitting of water molecules with electricity through electrolysis, is important to achieving future carbon neutrality, but current methods are inefficient and limit the commercial practicality of hydrogen-based technologies. Researchers in Malaysia created electrocatalyst WS2/N-rGO/CC on a carbon cloth that was bound to reduced graphene oxide (rGO), a two-dimensional lattice semiconductor, combined with a very small amount of nitrogen to alter the properties of the reduced graphene oxide semiconductor. Hydrothermal reaction converted 2D WS2 into microscopic, three-dimensional nanoflowers that increased the surface area of the electrocatalyst to improve […]
Device makes hydrogen from sunlight with record efficiency
Science Daily July 20, 2023 An international team of researchers (USA – Rice University, National Renewable Energy Laboratory, Lawrence Berkeley National Laboratory, Germany, France) designed and fabricated a conductive adhesive-barrier (CAB) that translates >99% of photoelectric power to chemical reactions. The CAB enabled halide perovskite-based photoelectrochemical cells with two different architectures that exhibited record STH efficiencies. The first, a co-planar photocathode-photoanode architecture, achieved an STH efficiency of 13.4% and 16.3 h to t60, solely limited by the hygroscopic hole transport layer in the n-i-p device. The second was formed using a monolithic stacked silicon-perovskite tandem, with a peak STH efficiency of […]
Revolutionary technique to generate hydrogen more efficiently from water
Phys.org October 27, 2022 Typically, electron transfer proceeds solely through either a metal redox chemistry or an oxygen redox chemistry without the concurrent occurrence of both metal and oxygen redox chemistries in the same electron transfer pathway. An international team of researchers (Singapore, USA – Brookhaven National Laboratory, China) has discovered an electron transfer mechanism that involves a switchable metal and oxygen redox chemistry in nickel-oxyhydroxide-based materials with light as the trigger. The proposed light-triggered coupled oxygen evolution mechanism requires the unit cell to undergo reversible geometric conversion between octahedron (NiO6) and square planar (NiO4) to achieve electronic states with […]
Producing hydrogen from seawater
Phys.org September 13, 2022 The direct electrolysis of seawater is greatly inhibited by the oxidation of Cl– to free chlorine, an undesirable, corrosive byproduct. To suppress the interference of Cl– and any other ion, researchers in Canada developed a freestanding, electrically conducting, 3D macroporous reduced graphene oxide (rGO) scaffold with cobalt oxide particles selectively deposited on the internal walls of its closed pores. The pore walls act as membranes composed of stacked rGO flakes; the nanochannels between rGO layers are permeable to water and gases while preventing the diffusion of dissolved ions such as Cl–. Due to this, the catalytic […]
New technique seamlessly converts ammonia to green hydrogen
Phys.org November 18, 2020 A team of researchers in the US (Northwestern University, industry) built a unique electrochemical cell with a proton-conducting membrane and integrated it with an ammonia-splitting catalyst to convert ammonia to hydrogen. The ammonia encounters the catalyst that splits it into nitrogen and hydrogen which is immediately converted into protons; protons are electrically driven across the proton-conducting membrane in the electrochemical cell. Continually pulling off the hydrogen drives the reaction to go further than it would otherwise. By removing hydrogen the reaction is pushed forward, beyond what the ammonia-splitting catalyst can do alone. The technique is a […]