The design of stable and highly efficient photocatalysts for harmful algae removal is critical to preserve the aquatic ecosystems. In this work, a series of Ag₂O/g-C₃N₄ with p-n heterojunction were synthesized by a chemical deposition method for photocatalytic algae removal under visible light. The effects of surface charge and composition ratio for the formation of heterojunction were investigated. The crystal phase, functional groups, morphology, optical properties, and elemental composition of the synthesized photocatalysts were also characterized. The experimental results showed that the photocatalytic activity of 14.3 wt% Ag₂O/B-g-C₃N₄ was outstanding for algae removal, suggesting that the bulk graphitic carbon nitride (g-C₃N₄) with negative surface charge was subject to combine with Ag₂O to form the heterojunction. In addition, the photocatalytic activity of the heterojunction was greatly affected by the composition ratio of synthesized materials. The optimal photocatalytic activity was observed when the composition ratio of Ag₂O and bulk g-C₃N₄ was 1:6, and the photocatalyst reached up to 99.94% removal of Microcystis aeruginosa (M. aeruginosa) after 6 h of photocatalytic reaction. Superoxide dismutase (SOD) and malondialdehyde (MDA) of algae cells decreased while catalase (CAT) increased during the experimental process. Furthermore, the antioxidant system collapsed and algal cell membrane was ruptured and damaged, resulting in the release of a large number of important ions (e.g., K⁺, Ca²⁺, and Mg²⁺), the decrease of chlorophyll a and phycobiliprotein (PB) contents, as well as the destruction of the photosynthetic system. Overall, the synthesized 14.3 wt% Ag₂O/B-g-C₃N₄ as a good photocatalyst has remarkable photostability under visible light and can be applied to alleviate cyanobacteria blooms.

设计稳定，高效的光催化剂以去除有害藻类对于保护水生生态系统至关重要。本文采用化学沉积法合成了一系列具有pn异质结的Ag ₂ O / gC ₃ N ₄，用于在可见光下去除光催化藻类。研究了表面电荷和组成比对异质结形成的影响。还表征了合成的光催化剂的晶相，官能团，形态，光学性质和元素组成。实验结果表明，14.3 wt％Ag ₂ O / BgC ₃ N ₄的光催化活性。在去除藻类方面表现出色，这表明具有负表面电荷的块状氮化碳石墨（gC ₃ N ₄）与Ag ₂ O结合形成异质结。另外，异质结的光催化活性受到合成材料的组成比的很大影响。当Ag ₂ O与块状gC ₃ N ₄的组成比为1：6时观察到了最佳的光催化活性，且铜绿微囊藻（M. aeruginosa）的去除率高达99.94％。）经过6小时的光催化反应。在实验过程中，藻类细胞的超氧化物歧化酶（SOD）和丙二醛（MDA）降低，而过氧化氢酶（CAT）升高。此外，抗氧化剂系统崩溃，藻类细胞膜破裂并受损，导致大量重要离子（例如K ⁺，Ca ²⁺和Mg ²⁺）的释放，叶绿素a和藻胆蛋白的减少（ PB）含量以及光合作用系统的破坏。总体而言，合成的14.3 wt％的Ag ₂ O / BgC ₃ N ₄作为良好的光催化剂，在可见光下具有显着的光稳定性，可用于缓解蓝藻水华。