Magnetic-field-induced activation of S-scheme heterojunction with core-shell structure for boosted photothermal-assisted photocatalytic H2 production

Photocatalytic H2 production through water splitting using semiconductor photocatalysts offers an economical and efficient approach to generate H2 with minimal environmental pollution to alleviate the energy crisis. Maximizing the utilization of the solar spectrum and essentially accelerating the separation and transfer of photogenerated electrons are crucial for enhancing the activity of the photocatalytic H2 production systems. Herein, Mn3O4@ZnIn2S4 (MO@ZIS) core-shell heterojunction photocatalysts were meticulously designed using a convenient water bath method to obtain a system that can achieve highly efficient photothermal-assisted photocatalytic H2 production induced by a magnetic field (MF). Remarkably, the optimal photocatalytic H2 production rate up to 33.29 mmol h-1 g-1 under the effect of applied MF with an apparent quantum efficiency (AQE) of 19.93 % at 420 nm were obtained over the optimal MO@ZIS-30 photocatalyst. The substantial enhancement of the photocatalytic activity in the MO@ZIS system was attributed to the synergy of magnetothermal effect induced by the magnetic field and the strong photo-thermal effect exhibited by MO, which significantly increases the heterojunction surface temperature of the photocatalyst and promotes the separation and transfer of photo-induced electron hole pairs, thus accelerating the surface hydrogen evolution dynamics. Furthermore, the S-scheme heterojunction formed between MO and ZIS in MO@ZIS core-shell heterojunction optimizes the carrier transfer path. This study presents an effective approach for the effective utilization of the multi-field synergistic enhancement of photocatalytic activity.