3D mesoporous black TiO_2-x/Ag nanosphere coupled with 2D g-C₃N₄ sheet ternary heterojunctions are successfully fabricated through a facile evaporation-induced self-assembly (EISA) process and photodeposition method, followed by a mild calcination (350 °C) under an argon atmosphere after an in situ solid-state chemical reduction strategy. The resultant mesoporous black TiO_2-x/Ag/g-C₃N₄ ternary heterojunctions with narrow band gap of ∼ 2.27 eV possess a relative high specific surface area of ∼ 100 m² g⁻¹, main pore size of 6.2 nm and the highest visible-light-driven photocatalytic property for degradation of methyl orange (97%) and methylene blue (99%). The apparent reaction rate constants (k) of mesoporous black TiO_2-x/Ag/g-C₃N₄ for methyl orange and methylene blue are ∼ 9 and 11 times higher than that of pristine TiO₂. The possible mechanism is proposed, and the excellent photocatalytic property can be ascribed to the introduction of Ti³⁺ self-doping and g-C₃N₄, which favor the visible light absorption and the separation of electron-hole pairs, the surface plasma resonance effect of Ag nanoparticle, and the mesoporous networks offer more surface active sites.

中文翻译：

---

介孔黑色TiO _2-x / Ag纳米球与gC ₃ N ₄纳米片耦合作为3D / 2D三元异质结可见光光催化剂

3D介孔黑色TiO _2-x / Ag纳米球与2D gC ₃ N ₄片材三元异质结的耦合通过一种简便的蒸发诱导自组装（EISA）工艺和光沉积方法，然后进行了适度的煅烧（350°C），成功地制得原位固态化学还原策略后，在氩气气氛下。窄带隙为〜2.27 eV的所得介孔黑色TiO _2-x / Ag / gC ₃ N ₄三元异质结具有〜100 m ²  g ^-1的相对较高的比表面积，主要孔径为6.2 nm，可见光驱动的光催化性能最高，可降解甲基橙（97％）和亚甲基蓝（99％）。介孔黑色TiO _2-x / Ag / gC ₃ N ₄对甲基橙和亚甲基蓝的表观反应速率常数（k）分别为原始TiO _2的约9倍和11倍。提出了可能的机理，并且将优异的光催化性能归因于Ti ³⁺自掺杂和gC ₃ N ₄的引入。，这有利于可见光的吸收和电子-空穴对的分离，银纳米粒子的表面等离子体共振效应，以及介孔网络提供更多的表面活性位点。