Dual p‐n Heterojunction and Photothermal Conversion Synergy Endows NiFe‐LDH/CoS/BiVO 4 Photoanodes With Enhanced Photoelectrocatalytic Performance

ABSTRACT The performance of photoanodes in photoelectrocatalytic (PEC) water splitting is limited by sluggish surface oxygen evolution reaction (OER) kinetics. Herein, a multifunctional p‐n heterojunction NiFe‐layered double hydroxide/CoS (NiFe‐LDH/CoS), acted as an oxygen evolution co‐catalyst (OECs), is introduced on BiVO 4 photoanodes for enhanced PEC performance. The formation of the p‐n heterojunction with CoS results in a positively charged NiFe‐LDH, thereby promoting the OER activity. Meanwhile, the p‐n heterojunction between CoS and BiVO 4 facilitates interfacial charge transport. Moreover, the PEC water oxidation process can be further modified via the photothermal effect of CoS. Due to the collective properties of p‐n heterojunction NiFe‐LDH/CoS cocatalysts, the obtained NiFe‐LDH/CoS/BiVO 4 photoanodes achieved a record photocurrent density of 6.97 mA cm −2 at 1.23 V versus reversible hydrogen electrode (RHE) assisted by near‐infrared light. These findings provide new insight into the rational regulating of surface reaction kinetics and cocatalyst/photoanode interface charge transfer simultaneously.