A kind of preparation method of cobalt phosphide modified molybdenum doped bismuth vanadate photoelectrode

Abstract

The invention discloses a method for preparing a molybdenum-doped bismuth vanadate photoelectrode modified by cobalt phosphide. First, a bismuth iodide oxide photoelectrode is prepared on the surface of a conductive glass by a deposition method, and a vanadium source and molybdenum are added dropwise on the bismuth iodide oxide photoelectrode. source solution, after annealing and cleaning, the molybdenum-doped bismuth vanadate photoelectrode was obtained, and then in the three-electrode system, cobalt phosphide was deposited on the surface of the molybdenum-doped bismuth vanadate photoelectrode through photo-assisted electrodeposition, and the new bismuth vanadate photoelectrode was obtained. The invention also discloses the application of the composite bismuth molybdovanadate photoelectrode in photoelectric catalytic water decomposition. The photoelectrode prepared by the present invention is used for photoelectrocatalytic water splitting to produce hydrogen. Doping molybdenum can effectively increase the concentration of carriers and increase the photocurrent, while electrodeposition of cobalt and phosphorus can effectively delay the recombination loss in the photoelectrode and increase the The lifetime of the photogenerated carriers can promote the oxygen evolution reaction on the surface of the photoelectrode, thereby improving the solar-to-hydrogen conversion efficiency of the semiconductor photoelectrode.

Description

technical field [0001] The invention belongs to the technical field of photoelectric materials, and in particular relates to a preparation method of a cobalt phosphide-modified molybdenum-doped bismuth vanadate photoelectrode and its application in photoelectric catalytic water decomposition. Background technique [0002] In order to realize the strategy of sustainable development, the development and utilization of renewable energy industry has become an important strategic goal of all countries in the world. Among them, solar energy, as a clean renewable energy source, has tens of thousands of times the reserves of other renewable energy sources; at the same time, solar energy hardly releases greenhouse gases during use, which helps to alleviate environmental pollution caused by extensive use of petroleum and fuel combustion. Environmental issues such as the greenhouse effect promoted by the solar energy have occupied an important position in the renewable energy industry....

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Problems solved by technology

The theoretical photolysis efficiency of bismuth vanadate is 9.2%, which is equivalent to a photocurrent density of 7.5mA cm -2 , but the actual photolysis efficiency of bismuth vanadate is much lower than its theoretical efficiency, and the current density of intrinsic bismuth vanadate photoelectrode is only 0.42mAcm -2 , as long as it is caused by the following three aspects: ① poor electron transport and high surface defects cause up to 60-80% charge recombination; ② slow oxygen evolution kinetics; ③ conduction band edge is slightly lower than the reversible hydrogen potential

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