Colorful Silver/Carbon Nitride Composites Obtained by Photoreduction

The Ag⁺ photoreduction by graphitic carbon nitride(g-CN) materials in a high concentration of Ag⁺ solution is reported, and a series of colorful Ag/g-CN composites is prepared and characterized. The chromatic change correlates to the carbon nitride materials synthesized at different heating temperatures(CN_T, where T means heating temperature), taking advantage of the different photocatalytic activities of different CN_T. The mechanism beneath this phenomenon is attributed to two factors: the particle size of Ag NPs and the coordinate effect of Ag NPs on CN_T sheets. Interestingly, the multicolors of Ag/g-CN composites display only on the CN_T materials synthesized from heating melamine-cyanuric acid precursor, but not on the CN_T from heating pure melamine. The color of the as-prepared Ag/g-CN composites can endure the corrosion of HNO₃ and ethanol, which shows a good chemical stability and may hint its application as chromophores.