Ag-Zn_3(VO_4)_2光催化剂催化降解甲基橙溶液

采用水热法结合高温热处理制备Ag-Zn_3(VO_4)_2光催化剂,研究催化剂在可见光下降解甲基橙溶液的性能,并考察催化剂用量、甲基橙溶液初始浓度、pH值、盐效应和H_2O_2用量对光催化性能的影响,评价Ag-Zn_3(VO_4)_2光催化剂的重复使用性能。结果表明,在催化剂用量2.0 g·L~(-1)、甲基橙溶液初始浓度20 mg·L~(-1)和溶液pH=6.2条件下光照反应5 h,甲基橙溶液脱色率可达99.18%,Na_2SO_4对光催化降解甲基橙起抑制作用,且随着溶液中盐浓度增加,抑制作用更明显。H_2O_2在一定浓度范围可促进光催化降解甲基橙,100 mL甲基橙溶液中30%H_2O_2加入量为1.0 mL时,甲基橙溶液脱色率可提高21.68个百分点。催化剂重复使用5次后,光照5 h的甲基橙溶液脱色率仍可达到75.99%。

Catalytic degradation of methyl orange by Ag-dopedZn3(VO4)2 photocatalyst

Ag-dopedZn₃(VO₄)₂ photocatalyst was prepared by hydrothermal method combined with subsequent heat treatment process.The properties of as-prepared photocatalyst for degradation of methyl orange under visible light were studied,and then the influence of catalyst dosage,initial concentrations and pH value of methyl orange solution,Na₂SO₄ concentrations andH₂O₂ amounts was investigated.The repeated use performance of Ag-Zn₃(VO₄)₂ photocatalyst was evaluated.The results showed that the degradation rate of methyl orange reached 99.18% under the optimal condition of catalyst dosage 2.0 g·L-1,initial concentrations of methyl orange solution 20 mg·L^-1,pH=6.2 and irradiation time 5 h.Addition of Na2SO4 inhibited photocatalytic degradation of methyl orange,and the inhibition action strengthened as the salt concentration increased.H₂O₂ accelerated photocatalysis in a certain concentration range,and the degradation rate of methyl orange could be improved by 21.68 percentage points under the condition of methyl orange solution 100 mL and 30% H₂O₂ amount 1.0 mL.After five recycling runs,Ag-Zn₃(VO₄)₂ photocatalyst still kept 75.99% removal rate of methyl orange under the irradiation for 5 h.