Graphene Quantum Sheet Catalyzed Silicon Photocathode for Selective CO2 Conversion to CO |
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| Authors: | Ki Dong Yang Yoonhoo Ha Uk Sim Junghyun An Chan Woo Lee Kyoungsuk Jin Younghye Kim Jimin Park Jung Sug Hong Jun Ho Lee Hye‐Eun Lee Hui‐Yun Jeong Hyungjun Kim Ki Tae Nam |
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| Affiliation: | 1. Department of Materials Science and Engineering, Seoul National University, Seoul, South Korea;2. Graduate School of EEWS, Korea Advanced Institute of Science and Technology, Daejeon, South Korea |
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| Abstract: | The reduction of carbon dioxide (CO2) into chemical feedstock is drawing increasing attention as a prominent method of recycling atmospheric CO2. Although many studies have been devoted in designing an efficient catalyst for CO2 conversion with noble metals, low selectivity and high energy input still remain major hurdles. One possible solution is to use the combination of an earth‐abundant electrocatalyst with a photoelectrode powered by solar energy. Herein, for the first time, a p‐type silicon nanowire with nitrogen‐doped graphene quantum sheets (N‐GQSs) as heterogeneous electrocatalyst for selective CO production is demonstrated. The photoreduction of CO2 into CO is achieved at a potential of ?1.53 V versus Ag/Ag+, providing 0.15 mA cm?2 of current density, which is 130 mV higher than that of a p‐type Si nanowire decorated with well‐known Cu catalyst. The faradaic efficiency for CO is 95%, demonstrating significantly improved selectivity compared with that of bare planar Si. The density functional theory (DFT) calculations are performed, which suggest that pyridinic N acts as the active site and band alignment can be achieved for N‐GQSs larger than 3 nm. The demonstrated high efficiency of the catalytic system provides new insights for the development of nonprecious, environmentally benign CO2 utilization. |
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| Keywords: | carbon dioxide reduction carbon quantum sheets photovoltaic devices |
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