二氧化钛/竹炭复合材料的吸附-光催化降解苯酚的动力学研究

以竹炭作为纳米二氧化钛（TiO₂）粒子的载体物质，制备了二氧化钛/竹炭复合材料，并以苯酚为模型物质，对其光催化性能进行了研究。研究表明，此复合材料对苯酚具有较强的吸附性能，其中吸附平衡常数K_a为0.007 7 L·mg^－1，K_a与苯酶吸咐平衡质量浓度ρ_e的乘积为0.25 ～ 1.35，二氧化钛/竹炭复合体的吸附作用不能忽略。根据L-H（Langmuir-Hinshelwood）方程积分所得分数级动力学方程较一级动力学方程能更好地描述其光催化降解规律，相应的光催化降解动力学方程为ln ρ － 0.007 7ρ = 6.58 － 0.002 39t（ρ为苯酚质量浓度，t为光照时间）。图6参14

Kinetic behavior of adsorption and photo-catalytic degradation of phenol in TiO_2/bamboo charcoal composite

TiO_2/bamboo charcoal composite was prepared by loading TiO_2 into bamboo charcoal.The photocatalytic activity of TiO_2/bamboo charcoal composite was evaluated using phenol as a model substrate.The experimental results demonstrated that TiO_2/bamboo charcoal composite had good adsorption capacity.The adsorption equilibrium constant(K_a)was 0.007 7 L·mg~(-1),K_aρ_e(ρ_e referred to equilibrium adsorption concentration of phenol)was from 0.25 to 1.35.It Was found that the Langmuir-Hinshelwood model in its integral form in describing the fraction order kinetics of phenol photocatalytic degradation in the TiO_2/bamboo charcoal composite were better than its simplified form as a first-order reaction model,since the significant substrate adsorption on the catalysts was not negligible,the corresponding photocatalytic degradation reaction equation was:lnρ-0.007 7_ρ=6.58-0.002 39_t(ρ referred to phenol concentration,and t referred to adsorption time).