Key role of hydrochar in heterogeneous photocatalytic degradation of sulfamethoxazole using AgPO-based photocatalysts.

To overcome the practical application limitations of AgPO such as photocorrosion and relatively low efficiency of photogenerated carrier seperation, AgPO particles were loaded onto hydrochar. The particles in the composite had a smaller crystallite size and different phase structure with more edges than pure AgPO particles. The as-prepared composite catalyst exhibited a different photocatalytic performance for sulfamethoxazole (SMX) degradation when varying the mass ratio of hydrochar and AgPO. In addition to higher SMX degradation efficiency, the composite exhibited much higher TOC degradation efficiency, recycling stability, and less-toxic intermediate production. The composites enhanced visible light response, and accelerated electron transfer and photogenerated carrier separation as well. The addition of HO to the photocatalytic system enhanced the photocatalytic activity of the composite catalyst. According to a mechanistic examination, the hole (h) is the dominant reactive species for SMX degradation. This study provides new insight into high-efficiency, low cost, and easily prepared photocatalysts for pollution removal from water.