Modification of TNF@UiO-66 composite by amine functionalized (TEPA) to improve photoconversion of CO2 using visible light: Investigation of intrinsic kinetic study and optimization

In this work, 25 % weight percentages of UiO-66 in TiO2 nanoflower composite was treated with varying quantities of Tetraethylenepentamine (TEPA) to improve photoconversion of CO2 into fuel using visible light (VL). The results revealed that maximum production rates of CH4 and CH3OH on TNF@25 %U-TEPA(2) sample were 64.59 and 2.47 µmol gcat−1 h−1, respectively, at the optimum conditions of V-LP=150 W, PCO2 =73 KPa, PH2O =15 KPa and T=332.15 K. 15 LHHW models were evaluated based on different assumptions of rate determining step and the most abundant surface intermediate to obtain kinetics of the CO2 photoconversion. The chosen model was the one that was closest to the experimental data. Furthermore, the kinetic rate and adsorption coefficients at T= 298.15–338.15 K and V-LP=150 W were obtained for the best-selected model. Finally, at T= 298.15–338.15 K, the activity energy of the produced CH4 was determined as 3.6 kJ mol−1. •Adding TEPA to TNF@25 %U improved the photoconversion performance of CO2 under visible light.•At PCO2 = 73 KPa, T=332.15 K, PH2O = 0.15KPa and V-LP=150 W, optimal conditions were obtained.•e-/h+ transfer between the TNF@25 %U-TEPA composite was consistent with the Z-scheme heterojunction.•15 models of LHHW were evaluated based on different assumptions of the RDS and MASI.•At T= 298.15–338.15 K, the activity energy of the produced CH4 was calculated to be 3.6 kJ.mol−1.