Sung P.-H.Huang C.-Y.Lin C.-Y.Chung P.-W.Chang Y.-C.Chen L.-C.Chen H.-Y.Liao C.-N.Chiu E.-L.Wang C.-Y.LI-CHYONG CHEN2022-08-092022-08-09202222129820https://www.scopus.com/inward/record.uri?eid=2-s2.0-85125038542&doi=10.1016%2fj.jcou.2022.101920&partnerID=40&md5=22452c87c79e8d93fea80a128628dafdhttps://scholars.lib.ntu.edu.tw/handle/123456789/616357Excess carbon dioxide emission accompanied by gross fossil fuel consumption has worsened the global warming crisis in recent decades. Photo-induced conversion of CO2 into hydrocarbons is a potential solution to mitigate both energy and environmental problems. However, conventional photocatalysts suffer low efficiency in CO2 conversion with often C1 and/or C2 products. In this work, pyrolyzed cobalt type zeolitic imidazolate framework (ZIF-67), namely ZIF-derived carbon (ZDC) with residual Co nanoparticles and the corresponding ZDC/TiO2 composite (ZDC/T), were adopted as gas-phase CO2 reduction photocatalysts. The ZDC photocatalyst is inclined to form C2 compound (acetaldehyde), while the ZDC/T composite has high selectivity in C3 product (acetone). High pyrolysis temperature would degrade the photocatalytic performance in neat ZDC due to enhanced cobalt aggregation and nitrogen loss after breaking ZIF-67 Co-N coordination. Alternatively, the pyrolyzed ZDC/T revealed superior photocatalytic CO2 reduction performance because the Co-N bonds were found to decrease without changing Co nanoparticle size and dissociation of nitrogen notably. In conclusion, we synthesized novel photocatalysts for multi-carbon (C2-C3) products with high selectivity, and provided a plausible mechanism to illustrate the formation process of multi-carbon products during photoreduction of CO2. © 2022 Elsevier Ltd.CO2reduction reaction;Photocatalysis;Zeolite imidazolate framework;ZIF derived carbonAcetone;Carbon dioxide;Cobalt;Fossil fuels;Global warming;Nanoparticles;Nitrogen;Pyrolysis;Titanium dioxide;CO 2 reduction;Co Nanoparticles;CO2 reduction;CO2reduction reaction;Derived carbons;Imidazolate;Photo-catalytic;Reduction reaction;Zeolite imidazolate framework;ZIF derived carbon;Zeolitesjournal article10.1016/j.jcou.2022.1019202-s2.0-85125038542