Synergy of photothermal effect and internal electric field for accelerated interfacial electron transfer in FeCoP@NC/MnCdS toward full-spectrum photocatalytic H2 evolution

Constructing heterojunctions that synergistically utilize both light and thermal energy is an effective strategy for achieving efficient photocatalytic hydrogen evolution. In this work, a photothermal-responsive FeCoP@NC/MnCdS Schottky junction was successfully constructed by loading MnCdS nanorods onto amorphous FeCoP@NC for full-spectrum photocatalytic H2 evolution. The amorphous nitrogen-doped carbon layer FeCoP (FeCoP@NC) derived from in situ phosphorization of a Fe-Co Prussian blue analogues, which provides a 3D conductive framework with strong broad-spectrum absorption. Infrared thermal imaging confirms that the FeCoP@NC significantly elevates the local temperature under illumination, indicating efficient photothermal conversion. The generated thermal energy not only accelerates interfacial reaction kinetics but also synergistically enhances charge separation. Combined density functional theory (DFT) calculations and in situ X-ray photoelectron spectroscopy (XPS) reveal the establishment of an internal electric field at the FeCoP@NC/MnCdS Schottky junction interface, which drives directional electron transfer from MnCdS to FeCoP@NC. Importantly, the photothermal effect further accelerates the electron transfer process by reducing kinetic barriers, creating a synergistic enhancement through thermal-effect and internal electric field driving for carrier separation and utilization. As a result, the optimal 20FCP@NC/MCS composite exhibits an excellent H2 evolution rate of 7.08 mmol g−1 h−1, which is 7.14 times higher than that of pristine MnCdS (0.87 mmol g−1 h−1), respectively. This work provides an effective design strategy and research insights for developing photothermally assisted high-performance full-spectrum photocatalysts.