Metal doped graphitic carbon nitride prepared by a bubbling template method for photo-degradation of organic pollutants

A bubbling template method was used to prepare metal-doped graphitic carbon nitride (g-CN), with ammonium salts as the bubbling templates. Effects of metal types, metal loading, as well as the species and dosage of ammonium salts, on the structure, physicochemical properties and catalytic performances of g-CN were systematically investigated. Photocatalytic degradation of rhodamine B (RhB) was used as a model reaction to evaluate the catalytic performances of the materials. The results indicated that K0.02-CN(CA-3), which was prepared with K doping and with ammonium carbonate as the bubbling template, exhibited the best activity, with 99.7% RhB conversion obtained at 17.5 min, which is 3.2 times higher than that of g-CN. This can be attributed to the improved surface area, widened light absorption range and enhanced electron–hole separation efficiency of K0.02-CN(CA-3), as compared to these of g-CN. This material was also active for photo-degradation of other pollutants and has good reusability. A sketchy mechanism indicating the reactive intermediates of reaction was proposed.