Low-overpotential selective reduction of CO2 to ethanol on electrodeposited CuxAuy nanowire arrays

Direct electrochemical reduction of CO2 to multicarbon products is highly desirable, yet challenging. Here, we present a potentiostatic pulse-electrodeposition of high-aspect-ratio CuxAuy nanowire arrays (NWAs) as high-performance electrocatalysts for the CO2 reduction reaction (CO2RR). The surface electronic structure related to the Cu:Au ratio in the CuxAuy NWAs could be facilely modulated by controlling the electrodeposition potential and the as-fabricated CuxAuy NWAs could be directly used as the catalytic electrode for the CO2RR. The morphology of the high-aspect-ratio nanowire array significantly lowers the onset potential of the alcohol formation due to the diffusion-induced enhancement of the local pH and CO concentration near the nanowire surface. Besides, the properly adjusted surface electronic structure of the CuxAuy NWA enables the adsorption of CO and facilitates the subsequent CO reduction to ethanol via the C-C coupling pathway. Owing to the synergistic effect of morphology and electronic structure, the optimized CuxAuy NWA selectively reduces CO2 to ethanol at low potentials of -0.5——0.7 V vs. RHE with a highest Faradaic efficiency of 48%. This work demonstrates the feasibility to optimize the activity and selectivity of the Cu-based electrocatalysts toward multicarbon alcohols for the CO2RR via simultaneous adjustment of the electronic structure and morphology of the catalysts.

Hybrid TaON/LaTiO_(2)N photoelectrode for water oxidation

Efficient and stable photoelectrodes for water oxidation are highly desirable in the field of photoelectrochemical(PEC)water splitting.However,photoelectrodes with low externally applied bias usually exhibit weak photocurrent and vice versa.Herein,novel and efficient CoO_(x)-TaON/LTON composite photoanodes have been successfully prepared by a microwave assisted method followed with a particle transfer procedure.The obtained photoanode generated an anodic photocurrent of∼7.2 mA cm^(−2) at 1.2 V_(RHE) and initiated the anodic photourrent at∼0.5 V_(RHE).The HC-STH of the composite photoelectrode reached 1.0%at 1.2 V_(RHE).Further,stoichiometric oxygen and hydrogen are stably produced on the photoanode and the counter electrode with a Faraday efficiency of unity for 2 h.