Boosting hydrogen production via alkaline water splitting: Impact of Ag doping in Gd2O3 nanosheet arrays

• Published in: International journal of hydrogen energy 2024-09
• Main Authors: Manzoor, Sumaira, Ali, Shahid, Mansha, Muhammad, Safronova, Anastasia V., Altaf, Faizah, Khan, Safyan Akram, Allakhverdiev, Suleyman I.
• Format: Article
• Language: English
• Subjects: Ag doping; Alkaline media; Gadolinium oxide; HER; Nanosheets; OER
• ISSN: 0360-3199
• DOI: 10.1016/j.ijhydene.2024.09.220

Hydrogen is a preferable renewable energy carrier in decarbonization efforts to develop sustainable and carbon-free economies due to its high energy density and absence of pollutant emissions during combustion. Among others, electrochemical water splitting (EWS) is a sustainable and eco-friendly technology for producing green hydrogen, representing an essential initial step towards achieving carbon neutrality. In this study, we synthesized a bifunctional electrocatalyst by vertically anchoring Ag-doped Gd2O3 nanosheet arrays onto a three-dimensional nickel foam (NF) substrate. The developed materials were thoroughly investigated using various analytical techniques. Furthermore, the electrocatalyst effectively performed oxygen evolution reactions (OER) and hydrogen evolution reactions (HER). The Ag4%-Gd2O3/NF exhibited boosted HER activity, achieving higher current densities ranging from 10 to 400 mA cm−2 at an overpotential between 14 and 122 mV. This study also highlights the considerable impact of metal sites in both Ag4%-Gd2O3/NF and Gd2O3/NF on the HER catalytic process. Similarly, the Ag4%-Gd2O3 electrocatalyst exhibited superior OER activity, with an overpotential of 209 mV at 10 mA cm−2. The optimized composition also shows Tafel slope of 25 and 20 mVdec−1. Furthermore, Ag4%-Gd2O3 demonstrated the ability to generate oxygen gas bubbles in approximately 20 h for OER, making it an attractive material for energy conversion and storage devices. [Display omitted] •Novel vertically anchoring Ag-doped Gd2O3 nanosheet arrays were developed.•Ag4%-Gd2O3/NF exhibited OER activity with onset potential (1.4 V.•TOF achieves a higher current density of 300 mAcm−2 at only 1.56 V vs. RHE.•Ag4%-Gd2O3/NF performed admirably, requiring only 1.42 V in overall water splitting.