Construction of Mn 0.2 Cd 0.8 S/NiO p – n Heterojunction for Boosted Photothermal‐Assisted Photocatalytic H 2 Evolution

ABSTRACT Photothermal effect‐assisted photocatalytic H 2 evolution has emerged as a focal point in the research of solar‐to‐hydrogen energy conversion. Herein, loading black NiO microspheres on polyhedral Mn 0.2 Cd 0.8 S (MCS) surface led to the successful construction of p−n MCS/NiO heterojunction that can efficiently promote photon‐generated carrier spatial separation. The remarkable photothermal effect of black NiO nanosheets enabled surface temperature of the optimal MCS/NiO composite to reach 97°C under ultraviolet‐visible‐near infrared (UV‐Vis‐NIR) light irradiation for 60s. Owing to the synergistic effect of p−n heterojunction and photothermal self‐heating effect, the maximum H 2 evolution rate over MCS/NiO‐5 wt% composite reached 35.89 mmol g −1 h −1 by illuminating with UV‐Vis‐NIR light. This work proposes a new approach on utilizing black NiO as photothermal material to develop photothermal‐assisted p−n heterojunction‐based photocatalytic system toward H 2 evolution.