Co-g-C3N4/La-TiO2复合材料光催化降解废水中乙基黄药

为了降解选矿废水中残留的浮选药剂乙基黄药，采用溶胶-凝胶法制备了一种复合型光催化材料Co-g-C3N4/La-TiO2，通过SEM、XRD、UV-Vis、光致发光光谱和XPS等对样品的形貌、晶型结构、光化学性质 和表面化学性质进行表征，研究了催化剂用量、模拟废水pH、乙基黄药初始浓度和时间对光催化效果的影响，并利用活性自由基捕捉试验确定光催化过程中起作用的活性基团。结果表明：Co-g-C3N4/La-TiO2中La和Co 以La3+和Co2+形式存在，其禁带宽度减小，吸收带边红移，光催化效率较高。在催化剂投加量为1 g/L，乙基黄药浓度为60 mg/L，pH为10的条件下，光催化60 min后乙基黄药的降解率达到了99.1%。空穴（h+）、羟基 自由基（·OH）、超氧自由基（·O2-）都在光催化氧化降解乙基黄药的过程中起到了重要作用，对光催化的贡献程度为：·OH＞h+＞·O2-。

Photocatalytic Degradation of Ethyl Xanthate in Wastewater by Co-g-C3N4/La-TiO2 Composite Material

In order to degrade the flotation agent ethyl xanthate remaining in the beneficiation wastewater,a composite photocatalytic material Co-g-C₃N₄/La-TiO₂ was prepared by the sol-gel method. The morphology,crystal structure,photochemical properties and surface chemical properties of the samples were characterized by SEM,XRD,UV-Vis,PL and XPS spectrum.The effects of catalyst dosage,simulated wastewater pH,initial concentration of ethyl xanthate and time on the photocatalytic effect were studied. Free radical capture experiments have also been carried out to determine the active groups that play a role in the photocatalysis process. The results showed that La and Co in Co-g-C₃N₄/La-TiO₂ exist in the form of La3+and Co²⁺. The band gap decreases and the absorption band edge was red-shifted,thus the photocatalytic efficiency is high. Under the conditions of catalyst dosage of 1 g/L,ethyl xanthate concentration of 60 mg/L,and pH of 10,the degradation rate of ethyl xanthate reached 99.1% after 60 minutes of photocatalysis reaction. Holes(h⁺),hydroxyl radicals(·OH)and superoxide radicals(·O₂^-)all have a great contribution to the degradation of ethyl xanthate during the process of photocatalytic oxidative,and the degree of contribution is ranked as ·OH>h⁺>·O₂^-.