埃洛石/g-C_3N_4-Cu_(2+1)O催化剂的制备及催化性能研究

Preparation of Halloysite/g-C_3N_4-Cu_(2+1)O and Its Catalytic Performance

文章以埃洛石(HNTs)、g-C_3N_4和硝酸铜为原料,一步合成了埃洛石/g-C_3N_4-Cu_(2+1)O催化剂。采用X射线衍射仪(XRD)、扫描电镜(SEM)、比表面积测定仪(BET)、程序升温还原(TPR)对催化剂进行了表征。研究了埃洛石/g-C_3N_4-Cu_(2+1)O对结晶紫的吸附性能、光催化降解性能和催化氧化CO性能。结果表明,将Cu_(2+1)O负载到埃洛石和g-C_3N_4的表面能显著地改善Cu_(2+1)O的分散性,减小Cu_(2+1)O的粒径和增强Cu_(2+1)O的热稳定性。当埃洛石、g-C_3N_4和Cu_(2+1)O的质量之比为5∶10∶4时,催化剂具有最优的光催化和低温催化活性。在最优条件下,该催化剂对结晶紫的吸附率为58.64%;添加6‰的H2O2水后,对结晶紫的降解率为97.53%。在温度为200℃时,催化剂连续催化氧化CO 12 h时,CO的转化率仍为92.5%。催化剂具有较好催化活性的原因可能是催化剂中的g-C_3N_4和Cu_(2+1)O存在较强的协同作用。另外,催化剂具有较大的比表面积,Cu_(2+1)O在埃洛石/g-C_3N_4上较好的分散性和较小的Cu_(2+1)O粒径也能显著增强催化剂的催化活性。

A novel catalyst used for treatment of dyestuff wastewater was developed in a bench scale experiment. Preparation of the catalyst involved processes of one-step synthesis of a, halloysite/g-C3N4-Cu（2＋1）O, with halloysite, g-C3N4 and cupric nitrate as materials, and characterization of the catalyst by using XRD, SEM, BET（Brunauer-Emmett-Teller） and TPR（temperature-programmed reduction）. And the adsorption of crystal violet onto the catalyst（halloysite/g-C3N4-Cu（2＋1）O） and the performances of the catalyst＇s photocatalytic degradation and catalytic oxidation of CO were investigated. The results of the experiment showed that the dispersibility of Cu（2＋1）O was improved and thermo-stability of Cu（2＋1）O was strengthened; when the mass ratio of halloysite to g-C3N4 and to Cu（2＋1）O was 5∶10∶4, the catalyst behaved in the best performances in terms of photo-catalytic activity and low-temperature catalytic activity; the degradation rate of crystal violet can reach up to 97.53% using this catalyst with the addition of 6‰ H2 O2 when the phtocatalytic reaction run for 50 min. Meanwhile, the catalyst maintained CO conversion rate up to 92.5% when the temperature was at 200 ℃ and the continuous catalytic oxidation of CO kept for 12 h.In conclusion, it was found that the strong adsorption and catalytic capacities of halloysite/g-C3N4-Cu（2＋1）O were likely attributed to the synergetic effects existed between the π-orbital of g-C3N4 and d-orbital of Cu（2＋1）O. Besides, catalytic activity was enhanced owing to the catalyst＇s larger specific surface area and improved dispersibility and tiny size of particles of Cu（2＋1）O.