Au nanoparticles loaded on hollow BiOCl microstructures boosting CO2 photoreduction

Abstract

The BiOCl (BOC) synthesized by the water bath heating method was treated with sodium borohydride (NaBH4) to introduce oxygen vacancies (OVs). At the same time, Au nanoparticles were loaded to prepare a series of Au/BiOCl samples with different ratios. OVs and Au nanoparticles can promote the light absorption of host photocatalyst in the visible region. The calculated work function of BiOCl and Au can verify the existence of Ohmic contact between the interface of them, which is conducive to the separation of charge carriers. Through a series of photoelectric tests, it was verified experimentally that the separation of charge carriers is indeed enhanced. The high-energy hot electrons produced by Au under the surface plasmon resonance (SPR) effect can increase the counts of electrons to participate in the CO2 reduction reaction. Especially for 1.0%-Au/BOC, the yields of CO can reach 43.16 µmol g−1 h−1, which is 6.6 times more than that of BOC. Therefore, loading precious metal on semiconductors is an effective strategy to promote the photocatalytic performance of CO2 reduction reactions.