A novel S-scheme Au/g-C₃N₄/BiO_1.2I_0.6 plasmonic heterojunction was constructed by calcining a mixture of flower-like BiOI and Au/g-C₃N₄ nanosheets for the first time. This Au/g-C₃N₄/BiO_1.2I_0.6 heterojunction exhibited excellent photocatalytic activity in bisphenol AF (BPAF) degradation and Cr(VI) reduction with high cycle stability under visible light irradiation. In particular, the photocatalytic performance of the optimum material developed (4-Au/g-C₃N₄/BiO_1.2I_0.6) can reach 0.0174 min⁻¹ (apparent rate of BPAF degradation) and 0.0204 min⁻¹ (apparent rate of Cr(VI) reduction), which were 6.5 and 3.7 times that of pristine g-C₃N₄, respectively. The high photocatalytic performance was due to the high efficiency of charge separation, the excellent light absorption of localized surface plasmon resonance (LSPR) caused by the Au deposition, and the formation of S-scheme heterojunctions, which maintained strong photocatalytic reduction and oxidation activity. Noticeably, the charge density difference and band offsets of the g-C₃N₄/BiO_1.2I_0.6 were calculated. The results revealed that an internal electric field (IEF) was created, which further demonstrated the formation of an S-scheme photocatalytic mechanism.

首次通过煅烧花状BiOI和Au/gC ₃ N ₄纳米片的混合物构建了一种新型S型Au/gC ₃ N ₄ /BiO _1.2 I _0.6等离子体异质结。这种Au/gC ₃ N ₄ /BiO _1.2 I _0.6异质结在可见光照射下表现出优异的双酚AF（BPAF）降解和Cr（VI）还原的光催化活性和高循环稳定性。特别是，开发的最佳材料的光催化性能（4-Au/gC ₃ N ₄ /BiO _1.2 I _0.6）可以达到0.0174 min ^-1（BPAF降解的表观速率）和0.0204 min ^-1（Cr(VI)的表观还原速率），分别是原始gC ₃ N ₄的6.5和3.7倍。高光催化性能是由于电荷分离效率高，Au沉积引起的局域表面等离子共振（LSPR）的优异光吸收，以及S型异质结的形成，保持了很强的光催化还原和氧化活性。值得注意的是，gC ₃ N ₄ /BiO _1.2 I _{0.6的电荷密度差和能带偏移}进行了计算。结果表明，产生了内部电场（IEF），进一步证明了S型光催化机制的形成。