微米SiC/石墨烯复合物光催化降解罗丹明B

Photocatalytic Degradation of Rhodamine B with Micro-SiC/Graphene Composite Under Visible Light Irradiation

为发展低耗和环境友好的有机物降解技术,采用光催化还原制备微米级碳化硅(SiC)/石墨烯复合材料,XRD、FTIR、Raman光谱、XPS和SEM等手段表征其物相组成和形貌结构,并以罗丹明B(RhB)为模拟污染物,研究了复合材料在可见光照射下的光催化活性和稳定性;通过活性物种捕获实验初步探讨了RhB的光催化降解机制.结果表明,SiC与石墨烯复合延长了光生电子和光生空穴的寿命,提高了材料的光催化活性与稳定性.当SiC/石墨烯配比为1∶0.8时,光照60 min时RhB的降解率可以达到92.7%,降解过程符合一级反应动力学方程.光催化降解RhB过程中,主要活性物种的贡献依次为:光生空穴(h^+)>超氧阴离子自由基(·O2^-)>光生电子(e^-)>羟基自由基(·OH).

To develop low consumption and an environmentally friendly degradation technology for organic pollutants,micro-SiC/graphene composite materials were synthesized by photocatalytic reduction,and the composition and morphology of the prepared materials were characterized by XRD,FTIR,Raman spectroscopy,XPS,and SEM.Rhodamine B(RhB)was selected as the simulated pollutant to investigate the photocatalytic activity and stability of composite materials under visible light irradiation.The degradation mechanism was preliminarily discussed by active species capture experiments.Results show that the lives of photogenerated electron and photogenerated hole of SiC were prolonged when combined with graphene,which improved the photocatalytic activity and stability of composite materials.The degradation efficiency of Rh B reached 92.7%with the composite material of SiC/graphene ratio(1∶0.8)under 60 min irradiation,and the degradation process accorded with the first-order reaction kinetic equation.The contribution of main active species for photocatalytic degradation followed with a decreasing order of photogenerated hole(h^+),superoxide anion radical(·O2^-),photogenerated electron(e^-),and hydroxyl radical(·OH).