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Although g-C 3 N 4 (CN) materials have been extensively explored for the photocatalytic degradation of organic pollutants, their weak response to visible light and fast recombination of photoexcited electron-hole pairs restrain their practical applications. Herein, we deeply mediated the CN's energy-band structure, morphology, and surface properties by non-metal (P) and metal (Mo) co-doping based on the thermal treatment of a phosphomolybdic acid hydrate and dicyandiamide mixture in a straightforward one-step manner. Meanwhile, cyano groups and nitrogen vacancies were generated as a result of the co-doping, and the resulting P, Mo co-doped CN (PM-CN) exhibited thinner layers, smaller sizes, and superior visible-light harvesting capacity and charge separation efficiency. Consequently, highly active PM-CN was obtained for photocatalytic tetracyclines (TC) degradation, and the rate was calculated to be 0.01 min−1, 3.3 times greater than that of the pure CN, outstripping the single P- and Mo-doped counterparts. A free radical scavenging test demonstrated that the reactive species •O2− and h+ were critical in TC degradation. The present work is expected to shed light on co-doping CN with non-metal and metal elements to obtain high-performance, visible-light-responsive photocatalysts for practical environmental remediation. [ABSTRACT FROM AUTHOR]

Uniform doping is usually recognized as an efficient method for enhancing photocatalysis of TiO 2 , while non-uniform doping is generally supposed to be inefficient because of the inhomogeneous dispersion of dopants. However, in this study, we present the first example of non-uniform doping (with Au)-better enhanced photocatalysis of TiO 2 nanotubes, as compared to uniform doping, in terms of the photocatalytic organic dye degradation. The extent to which the non-uniform doping (achieved by liquid phase deposition (LPD)) can enhance photocatalysis is evaluated, along with a comparison with uniform doping. There exists an additional positive effect in the non-uniform doping system, that is, as generated interfaces between pure phase TiO 2 and Au-doped TiO 2 , in contrast to the uniform doping system leading to a positive “platinum island” effect. Such double beneficial effects contribute to the highest performance in the photocatalytic organic dye degradation for the Au-non-uniformly doped TiO 2 nanotubes as compared to other samples involved in this study. Both the “platinum island” and interfacial separation effects are helpful to isolate the photo-generated electrons and holes, resulting in enhanced photocatalytic activities. [ABSTRACT FROM AUTHOR]