Ti³⁺ self-doped mesoporous black TiO₂/SiO₂/g-C₃N₄ sheets heterojunctions are successfully prepared by a sol-gel strategy, followed by calcination at 450 °C and hydrogenation at 500 °C. The characterization results indicate that Ti³⁺ self-doped mesoporous black TiO₂/SiO₂/g-C₃N₄ sheets heterojunctions photocatalysts possess high surface area of ∼145.6 m² g⁻¹, large pore size of ∼4 nm and pore volume of ∼0.27 cm³ g⁻¹, respectively. The complete retention of the mesoporous frameworks is attributed to the addition of SiO₂, which not only retards the growth of TiO₂ crystals but also avoids the collapse of the channels even under high temperature calcination process. The prepared heterojunctions photocatalysts with narrow bandgap of ∼2.25 eV exhibit the excellent photocatalytic activity for degradation of phenol (98.5%), reduction of Cr⁶⁺ (97%) and photocatalytic hydrogen evolution (572.6 μmol h⁻¹ g⁻¹) under visible light irradiation, which is several times higher than that of pristine one. The outstanding photocatalytic property can be ascribed to the unique mesoporous framework enhancing the adsorption of pollutants and favoring the mass transfer, Ti³⁺ self-doping reducing the bandgap and extending the photoresponse to visible light region, the formation of heterojunctions preventing the recombination of photogenerated electrons and holes and benefiting their effective separation.

通过溶胶-凝胶策略成功制备了Ti ³⁺自掺杂的中孔黑色TiO ₂ / SiO ₂ / gC ₃ N ₄薄片异质结，然后在450°C煅烧并在500°C氢化。表征结果表明，Ti ³⁺自掺杂的介孔黑色TiO ₂ / SiO ₂ / gC ₃ N ₄片状异质结光催化剂具有约145.6 m ²  g ^-1的高表面积，约4 nm的大孔径和约3μm的孔体积。约0.27 cm ³  g ^-1， 分别。介孔骨架的完全保留归因于SiO _2的添加，这不仅阻碍了TiO ₂晶体的生长，而且即使在高温煅烧过程中也避免了通道的塌陷。制备的窄带隙为〜2.25 eV的异质结光催化剂对苯酚的降解（98.5％），Cr ^6+的还原（97％）和光催化氢释放具有优异的光催化活性（572.6μmolh ^-1  g ^-1））在可见光照射下，比原始的高几倍。出色的光催化性能可归因于独特的介孔骨架，可增强污染物的吸附并有利于传质，Ti ³⁺自掺杂可减少带隙并将光响应扩展至可见光区域，异质结的形成会阻止光生复合电子和空穴，有利于它们的有效分离。