TY  - JOUR
T1  - Highly activated phosphate-derived oxyhydroxide overlayer for enhancing photoelectrochemical ammonia oxidation-boosted hydrogen evolution
AU  - Pham, Phuong Thi
AU  - Kim, Jong Hun
AU  - Hong, Won Tae
AU  - Han, Hyungu
AU  - Roh, Seung Hun
AU  - Yu, Xu
AU  - Chae, Heeyeop
AU  - Park, Jongwook
AU  - Kim, Min-Cheol
AU  - Choi, Chang Hyuck
AU  - Kim, Jung Kyu
JO  - Chemical Engineering Journal
VL  - 506
SP  - 160053
PY  - 2025
DA  - 2025/01/15/
SN  - 1385-8947
DO  - https://doi.org/10.1016/j.cej.2025.160053
UR  - https://www.sciencedirect.com/science/article/pii/S1385894725008526
KW  - PEC ammonia oxidation reaction
KW  - Activated phosphate overlayer
KW  - BiVO
KW  - Hydrogen production
KW  - Ammonia to hydrogen conversion
AB  - Ammonia (NH3) oxidation reaction (AOR) has received great interest in recent years as an effective method to enable highly sustainable hydrogen (H2) storage and conversion. Here, we demonstrate an intensively enhanced photoelectrochemical (PEC) AOR-boosted H2 production with a highly activated bismuth-vanadium oxyhydroxide overlayer, derived from an overlaid thin phosphate layer, on BiVO4 (BVO) photoanode. A simple electrochemical (EC) activation is applied on a phosphate-modified bismuth vanadate (Pi-BVO) film to achieve the bimetallic oxyhydroxide overlayer on BVO (a-Pi-BVO) photoanode, which provides a high activity for enhancing the AOR kinetics. We confirm that the a-Pi-BVO photoanode follows pseudo-first order kinetics and demonstrates a 10-fold increase in PEC AOR kinetics, compared to pristine BVO at 0.77 V vs. reversible hydrogen electrode (RHE) in a dilute (500 ppm) NH3 aqueous media. In our solar-assisted overall ammonia electrolysis cell system with 2-electrode configuration, composed of PEC ammonia oxidation and EC hydrogen evolution reactions, a-Pi-BVO photoanode shows a 6.5-fold enhancement in H2 production compared to pristine BVO photoanode. This study demonstrates that the simple surface activation of the Pi-BVO photoanode enables highly active PEC AOR for efficient H2 production under dilute ammonia conditions, which is a promising strategy with applicability to practical wastewater applications.
ER  -