Construction of amorphous/crystalline Fe doped CoSe for effective electrocatalytic oxygen evolution

Herein, amorphous/crystalline Fe-doped CoSe was synthesized (Fe-CoSe/NF), and it exhibited high oxygen evolution reaction (OER) performance. The synergistic effect of the Fe dopant and the amorphous/crystalline structure is conducive to the formation of high valence Co3+ and Fe3+ active sites. Fe-CoSe/NF shows low overpotentials of 269 mV@50 mA cm-2 and 280 mV@100 mA cm-2.

Robust cellulose fiber/fibrous sepiolite coated RuO2-CoP aerogel as monolithic catalyst for hydrogen generation via NaBH4 hydrolysis

Commercial carriers have been used to prepare monolithic NaBH₄ hydrolytic catalysts, but the fixed structure and material limit the application scope and design freedom. Herein, the RuO₂-CoP catalyst is coated on the surface of fibrous sepiolite (RuO₂-CoP@aSep) by in-situ deposition, annealing in air and phosphating, which is constructed into the aerogel with cellulose nanofiber (CNF) and polyvinyl alcohol (PVA) by freeze drying process. The hydrogen generation rate (HGR) of RuO₂-CoP@aSep increases from 3655 to 10713mLmin^-1g_catalyst^-1 by adjusting the mass ratio of cobalt to ruthenium in RuO₂-CoP. Moreover, the optimized composite aerogel can get HGR (5268mLmin^-1g_catalyst^-1) by regulating its formulation, and the catalytic activity and mass loss rate of the aerogel maintains 76.6 and 0.92 % after five cycles of testing. The synergistic interaction between Ru and Co species, micro-nano porous structure, and structural coupling provide good catalytic activity and cycling performance, and show great potential in the design of controllable NaBH₄ hydrolyzed monolithic catalysts.

Active Sites Regulation for High-Performance Oxygen Evolution Reaction Electrocatalysts

Electrochemical water splitting to produce molecular hydrogen and oxygen provides a promising strategy engineering for scalable hydrogen production with high purity. Unfortunately, the sluggish kinetics of oxygen evolution reactions (OER) due to the interdependence multiple steps procedure require high overpotential to achieve appreciable catalytic current density, resulting in relatively low energy conversion efficiencies. Therefore, development of high-performance OER electrocatalysts is vital to drive the commercial application of water splitting. This review highlights current progress of representative catalyst electrocatalysts in the past decade. Active site regulation for excellent OER performance of precious metal single atoms catalyst, high-entropy alloy, transition metals oxides, transition metal chalcogenide are emphasized. And a more in-depth exploration of OER reaction mechanism by in situ technique and DFT results will be conducted. This review can provide the basis for the development and modification of OER electrocatalysts.