To overcome the shortcomings of fast recombination of photo-induced carriers and powder recycling difficulty of graphitic carbon nitride (g-C₃N₄), a powder suspension system containing TiO₂/g-C₃N₄ and a cement paste immobilization of TiO₂/g-C₃N₄ were fabricated through pyrolysis of urea and P25 TiO₂, and spraying method, respectively. The phase composition, microstructure, element chemical state, optical properties, and photocatalytic degradation of dyes were investigated. TiO₂ particles were attached closely to the surfaces of g-C₃N₄. TiO₂/g-C₃N₄ had broader light absorption ranges and a lower recombination rate of photo-induced carriers. During the photocatalysis, h⁺, •O₂^- and •OH were the main active species. The heterojunction structure of TiO₂/g-C₃N₄ belonged to a Z-scheme heterojunction. The TiO₂/g-C₃N₄ powders had ~ 97% degradation efficiency of rhodamine B (RhB) dyes after 40 min irradiation. After five cycles of degradation, the degradation efficiency reduced to ~ 67%. The TiO₂/g-C₃N₄ cement paste had superior degradation over RhB and methylene blue (MB). After five cycles of degradation, the photocatalytic cement paste still had higher efficiency, ~ 98% after 60 min degradation. A photocatalytic mechanism was proposed. TiO₂/g-C₃N₄ powders and TiO₂/g-C₃N₄ cement pastes can be one of highly promising photocatalysts for large-scale water treatment.

为了克服光诱导载流子快速重组的缺点和石墨氮化碳（gC ₃ N ₄）的粉末回收困难，含TiO ₂ / gC ₃ N ₄的粉末悬浮体系和固定化TiO ₂ / gC ₃的水泥浆N ₄分别通过尿素和P25 TiO _2的热解并通过喷涂法制备。研究了染料的相组成，微观结构，元素化学状态，光学性质和光催化降解。TiO ₂颗粒紧密附着在gC ₃ N ₄的表面上。TiO ₂ / gC ₃ N ₄具有较宽的光吸收范围和较低的光诱导载流子复合率。在光催化，H ⁺，•Ø ₂ ^-和OH•是主要的活性物质。TiO ₂ / gC ₃ N ₄的异质结结构属于Z型异质结。TiO ₂ / gC ₃ N ₄粉末在 照射40分钟后具有约97％的若丹明B（RhB）染料降解效率。经过五个降解周期后，降解效率降低至〜67％。TiO ₂ / gC ₃ N ₄水泥浆的降解性能优于RhB和亚甲基蓝（MB）。经过五个降解周期后，光催化水泥浆仍具有更高的效率， 降解60分钟后约为98％。提出了一种光催化机理。TiO ₂ / gC ₃ N ₄粉末和TiO ₂ / gC ₃ N ₄水泥浆可以成为大规模水处理中极有希望的光催化剂之一。