CdS nanorods decorated with non-precious metal Bi spheres for photocatalytic hydrogen production

Abstract

It is well known that precious metals decoration strategies can effectively improve the charge separation efficiency. Unfortunately, the high price limits their large-scale application. Nevertheless, the cheap transition metal Bi has a similar effect as precious metals. Therefore, we take a simple solvothermal method to reduce and aggregate Bi3+ into bismuth nano-spheres (Bi0). CdS nanorods were modified with Bi spheres to create a hybrid material called x% Bi–CdS, which combines a metal and a semiconductor for photocatalytic hydrogen production. The results of the experiment indicate that the hydrogen evolution rate of the 5% Bi–CdS sample is 1501.52 μmol g−1 h−1, which is 4.2 times greater than that of pure CdS nanorods. This significant enhancement in photocatalytic activity can be attributed to the presence of Bi spheres, which induce a surface plasmon resonance (SPR) effect. This effect boosts the absorption of visible light and enhances the separation efficiency of charge carriers. The study not only provides a solution for the preparation of low-cost CdS-based materials, but also confirms the feasibility of inexpensive Bi metals to replace precious metals as co-catalysts to improve the photocatalytic efficiency.