Facile fabrication of porous thin films of Bi_2O_3/Bi_2S_3 nanocomposite semiconductors at gas/liquid interface and their photoelectrochemical performances

摘要

Porous thin films of Bi_2O_3/Bi_2S_3 nanocomposite semiconductors were prepared rapidly at gas/liquid interface for the first time by contacting an acidic Bi(NO_3)_3 solution with vapors from ammonia water and ammonium sulfide solution. Hydrolysis of Bi~(3+) into Bi_2O_3 nanoparticles (NPs) and their partial sulfurization into Bi_2S_3 occurred atear the solution surface upon contacting the vapors of NH3 and H2S, respectively. Based on photoelectrochemical performances, the conditions were optimized for preparation of Bi_2O_3/Bi_2S_3 thin films by interfacial reactions and self-assembly of the in situ produced nanocomposites, including concentrations of Bi(NO_3)_3 and HNO_3, vapor sources, contact manners and contact times. The porous thin film of Bi_2O_3/Bi_2S_3 prepared under optimized conditions showed better photoelectrochemical performance than the respective thin films of Bi_2O_3 and Bi_2S_3 and their some other composites.