(1. 湖北工業(yè)大學(xué) 機(jī)械工程學(xué)院，武漢 430068；
2. 湖北工業(yè)大學(xué) 綠色輕工材料湖北省重點(diǎn)實(shí)驗(yàn)室，武漢 430068)
摘 要: 利用二氰二胺與尿素的復(fù)合粉末作為前驅(qū)體，通過簡(jiǎn)單的高溫?zé)Y(jié)法制備石墨相g-C3N4光催化劑。采用XRD、FESEM、TEM、BET、XPS和DRS等分析手段對(duì)g-C3N4的微觀結(jié)構(gòu)進(jìn)行表征，并考察尿素加入量、催化劑濃度、染料初始濃度、溶液pH值以及光源等對(duì)光催化降解甲基橙的影響。結(jié)果表明：復(fù)合粉末前驅(qū)體所制備的g-C3N4具有典型的多孔結(jié)構(gòu)，相比于純二氰二胺或純尿素所制備的產(chǎn)物具有更高的比表面積。隨著尿素含量增加，g-C3N4產(chǎn)物的禁帶寬度逐漸增大,而其表面的C和N摩爾比則從0.70降至0.60。可見光光催化降解甲基橙的實(shí)驗(yàn)結(jié)果顯示隨著尿素含量的增加，g-C3N4的光催化活性也隨之增強(qiáng)，表明g-C3N4的表面化學(xué)組成及其氧化還原能力對(duì)可見光光催化活性起主要作用，而比表面積起次要作用。
關(guān)鍵字: g-C3N4；甲基橙；尿素；二氰二胺；光催化
（1. School of Mechanical Engineering, Hubei University of Technology, Wuhan 430068, China;
2. Hubei Provincial Key Laboratory of Green Materials for Light Industry,
Hubei University of Technology, Wuhan 430068, China）
Abstract:g-C3N4 photocatalysts were prepared by high temperature calcination method using the mixture powders of melamine and urea as precursors. XRD, FESEM, TEM, XPS, BET and DRS were employed to characterize the microstructure of as-synthesized g-C3N4 photocatalysts. The influences of urea content (mass fraction) in mixture powders, photocatalysts concentration, initial dye concentration, pH value of solution, as well as the light sources on the methyl orange degradation efficiency, were evaluated. The results show that g-C3N4 photocatalysts synthesized by mixture powders present the typical porous structure, which exhibit the higher surface area than that prepared by pure melamine or pure urea. The band gap of g-C3N4 photocatalysts increases with the increase of urea content in mixture powders. However, the surface mole ratio of C and N decreases from 0.70 to 0.60. Methyl orange photodegradation results under visible light irradiation demonstrate the surface chemical composition and the redox ability of g-C3N4 plays a major role, while the surface area of photocatalysts plays a minor role.
Key words: g-C3N4; methyl orange; urea; melamine; photocatalysis
