Synthesis Of MSe₂（M=Co、Ni）Catalytic Material For Water Splitting

The completely water-splitting reaction could be divided to two half-reactions,the hydrogen evolution reaction(HER)at cathode and oxygen evolution reaction(OER)at the anode.Due to the completely different reaction pathways during water reduction and water oxidation process,there are limited reports on electrocatalysts that are bifunctionally active for both HER and OER.The recently developed transition-metal-chalcogenides have abundant elements and electronic structure,showing excellent chemical and physical properties.Carbon cloth(CC)is a cheap textile with high conductivity and excellent flexibility,and has been widely used as an electrode to support active measure and found that the as-prepared sample demonstrated excellent catalytic properties,which were proposed to be attributed to the high electronic mobility,facilitating electron transfer and reducing the combination,The main research contents are as follows:1.The CoSe2 nanosheets developed on high flexible carbon fiber substrate are synthesized via a simple two-step route.The scale-up and facile compound process only allows lower cost preparation of CoSe2 nanosheets and holds a promise to replace the noble metal catalysis for H2 production in viable water electrolytic systems.2.Combining the morphology controlling and phase engineering together to design high active hydrogen evolution reaction electrocatalysts.A three-dimensional(3D)hierarchical architecture with well-aligned NiSe2 nanosheets(NSs)vertically grafted on the 3D carbon cloth was successfully prepared via a facile two-step hydrothermal reaction.Our work suggests that the synergistic effect between morphology controlling and phase engineering would significantly optimize electrocatalytic HER activities.3.The as-prepared 3D NiSe2/CC structure can be directly used as binder-free flexible electrodes for cathode and anode,showing excellent overall water splitting activities.By selectively controlled synthesis of orthorhombic phase NiSe2 and pure cubic phase NiSe2,we experimentally reveal that the pure cubic phase possess the highest catalytic activity in alkali.