Bismuth oxyiodide-bismuth vanadium oxide heterojunction photocatalyst and preparation method thereof

The invention belongs to the technical field of semiconductor photocatalysis, and discloses a bismuth oxyiodide-bismuth vanadium oxide heterojunction photocatalyst and a preparation method thereof. The photocatalyst is a heterostructure formed by combination of bismuth oxyiodide ad bismuth vanadium oxide, and bismuth vanadium oxide nanoparticles are uniformly dispersed on bismuth oxyiodide nanoparticle surfaces. The preparation method comprises firstly dissolving bismuth nitrate pentahydrate and citric acid in diluted nitric acid and adjusting pH value, dissolving ammonium metavanadate and citric acid in distilled water and heating, and mixing the two solutions; and dissolving bismuth nitrate pentahydrate in glycol, dissolving potassium iodide KI in distilled water, mixing the two solutions and putting into the above mixed solutions, stirring, ageing, drying, calcining and grinding, so as to obtain the heterojunction photocatalyst. The synthesized photocatalyst possesses the typical heterostructure, possesses the characteristics of inhibiting electron-cavity recombination and effectively promoting carrier separation, and compared with a monomer bismuth vanadium oxide, the synthesized photocatalyst is relatively wide in photoresponse scope and relatively good in catalytic activity and stability.