Silver phosphate (Ag3PO4, APO) has attracted intense attention as a visible-light-driven photocatalyst, but its large-scale application is limited by severe charge recombination and inevitable photo-corrosion. Various rational APO-based heterostructures composed of APO nanoparticles (NPs) and band-matched semiconductor support are designed to address the above issues. Nevertheless, the size, density, stability, and dispersion of APO NPs are critical challenges for the photocatalytic performance of APO-based photocatalysts. Here, three-dimensional (3D) self-assembled TiO2 hierarchical spheres (THS) prepared by a simple one-step hydrothermal method are employed as innovative support, and ultrafine high-density APO NPs with an average size of about 3 nm are successfully deposited and uniformly dispersed throughout THS to form hierarchical THS/APO composites. The novel THS/APO microstructure provides abundant reactive sites for photocatalytic reactions and promotes the photogenerated charge separation and transfer due to the ultrafine size of APO NPs and the TiO2/APO Type-II heterojunction. As a result, the THS/APO composites show significant improvement in photocatalytic activity and stability in methylene blue (MB) degradation. The reaction constant of THS/APO composites far exceeds that of either THS or APO, roughly 16 and 7 times higher than that of THS and APO under full-spectrum light, and 41 and 4 times higher under visible light. Our results strongly suggest new insights into the low-cost, large-scale application of high-efficiency APO-based photocatalyst.

中文翻译：

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高密度超细 Ag3PO4 纳米粒子在 3D TiO2 分级球体上原位生长以增强有机污染物的光催化降解

磷酸银（Ag3PO4，APO）作为可见光驱动的光催化剂引起了广泛关注，但其大规模应用受到严重的电荷复合和不可避免的光腐蚀的限制。由 APO 纳米粒子 (NPs) 和能带匹配的半导体支撑组成的各种基于 APO 的合理异质结构旨在解决上述问题。然而，APO NPs 的尺寸、密度、稳定性和分散性是 APO 基光催化剂的光催化性能的关键挑战。在这里，采用简单的一步水热法制备的三维（3D）自组装二氧化钛分级球（THS）作为创新支持，和平均尺寸约为 3 nm 的超细高密度 APO NPs 成功沉积并均匀分散在整个 THS 中，形成分层的 THS/APO 复合材料。由于 APO NPs 的超细尺寸和 TiO2/APO II 型异质结，新型 THS/APO 微结构为光催化反应提供了丰富的反应位点，并促进了光生电荷的分离和转移。因此，THS/APO 复合材料在亚甲蓝 (MB) 降解中的光催化活性和稳定性方面表现出显着改善。THS/APO复合材料的反应常数远远超过THS或APO，在全光谱光下大约是THS和APO的16和7倍，在可见光下分别高41和4倍。我们的结果强烈暗示了对低成本的新见解，