Constructing S-scheme 2D/0D g-C_(3)N_(4)/TiO_(2) NPs/MPs heterojunction with 2D-Ti3AlC2 MAX cocatalyst for photocatalytic CO_(2) reduction to CO/CH_(4) in fixed-bed and monolith photoreactors  

作　　者：Muhammad Tahir Beenish Tahir 

机构地区：[1]Department of Chemical Engineering,School of Chemical and Energy Engineering,Universiti Teknologi Malaysia,81310,UTM Johor Bahru,Malaysia [2]Chemical and Petroleum Engineering Department,UAE University,P.O.Box 15551,Al Ain,United Arab Emirates

出　　处：《Journal of Materials Science & Technology》2022年第11期195-210,共16页材料科学技术（英文版）

基　　金：Ministry of Higher Education (MOHE),Malaysia,for financial support of this work under Fundamental Research Grant Scheme (No.R.J130000.7851.5F384)。

摘　　要：Exfoliated 2D MAX Ti_(3) AlC_(2) conductive cocatalyst anchored with g-C_(3)N_(4)/TiO_(2) to construct 2D/0D/2D het-erojunction has been explored for enhanced CO_(2) photoreduction in a fixed-bed and monolith photoreac-tor.The TiO_(2) particle sizes(NPs and MPs)were systematically investigated to determine effective metal-support interaction with faster charge carrier separation among the composite materials.When TiO_(2) NPs were anchored with 2D Ti_(3) AlC_(2) MAX structure,10.44 folds higher CH_(4) production was observed com-pared to anchoring TiO_(2) MPs.Maximum CH_(4) yield rate of 2103.5μmol g^(−1) h^(−1) achieved at selectivity 96.59%using ternary g-C_(3)N_(4)/TiO_(2)/Ti_(3) AlC_(2)2D/0D/2D composite which is 2.73 and 7.45 folds higher than using binary g-C_(3)N_(4)/Ti_(3) AlC_(2) MAX and TiO_(2) NPs/Ti_(3)AlC_(2) samples,respectively.A step-scheme(S-scheme)photocatalytic mechanism operates in this composite,suppressed the recombination of useful electron and holes and provides higher reduction potential for efficient CO_(2) conversion to CO and CH_(4).More im-portantly,when light intensity was increased by 5 folds,CH_(4) production rate was increased by 3.59 folds under visible light.The performance of composite catalyst was further investigated in a fixed-bed and monolith photoreactor and found monolithic support increased CO production by 2.64 folds,whereas,53.99 times lower CH_(4) production was noticed.The lower photocatalytic activity in a monolith photore-actor was due to lower visible light penetration into the microchannels.Thus,2D MAX Ti_(3) AlC_(2) composite catalyst can be constructed for selective photocatalytic CO_(2) methanation under visible light in a fixed-bed photoreactor.

关 键 词：Photocatalytic CO_(2)methanation Exfoliated 2D MAX Ti_(3)AlC_(2) g-C_(3)N_(4)/TiO_(2) Fixed-bed reactor Monolith photoreactor Solar energy 

分 类 号：TQ426[化学工程] X701[环境科学与工程—环境工程]