120th General Meeting of the KCS

Type Poster Presentation
Area Environmental Energy
Room No. Exhibition Hall 2+3
Time 10월 19일 (목요일) 11:00~12:30
Code ENVR.P-519
Subject Enhanced Hole Mobility on Electrochemically Synthesized p-type CuAlO2 Photoelectrodes for Efficient Solar Hydrogen Production [우수포스터상]
Authors Seung Yo Choi, GUANGXIA PIAO1, Hyunwoong Park2,*
School of Energy Engineering, Kyungpook National University, Korea
1School of Energy Engineering, Kyungpook National University, China
2Division of Energy Engineering, Kyungpook National University, Korea
Abstract Delafossite CuAlO2 photoelectrodes are synthesized via an electrodeposition of Cu(II) and Al(III) onto transparent conducting oxide (TCO) substrates in water and dimethylsulfoxide (DMSO) solvents followed by annealing in air and Ar. Optimized CuAlO2 electrodes (synthesized in DMSO and annealed in Air) posses the suitable energetics for H2 production under sunlight (optical bandgap of ~1.4 eV and conduction band level of ~ 0.24 VRHE). They exhibit the photocurrent onset potential of ~+0.9 VRHE along with the Faradaic efficiency of ~70% at +0.3 VRHE in alkaline solution (1 M KOH) under simulated sunlight (AM 1.5; 100 mW·cm2). Addition of sacrificial hole scavengers significantly improves the PEC performance of CuAlO2 by a factor of 8 along with the faradaic efficiency of ~100%. This indicates that the hole transfer limits overall PEC performance. This challenge is addressed by employing a ~150 nm-thick Au film-coated TCO substrate for CuAlO2 deposition. In the absence of the hole scavengers, the H2 production with the Au-underlayer CuAlO2 photoelectrode (Au/CuAlO2) was three-fold higher than that with bare CuAlO2, while the Faradaic efficiencies at +0.3 and +0.55 VRHE were ~100%. This work was financially supported by the Korea Ministry of Environment as Waste to Energy Recycling Human Resource Development Project (YL-WE-17-001), and Nano-Material Technology Development Program (NRF-2016M3A7B4908169).
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