Fabrication and OER/HER electrochemical activity of Sm, Al assisted g-C3N4 nanocomposite for alkaline water splitting

Abstract

The quest for highly efficient and reasonably priced electrocatalysts for water splitting is the primary goal of sustainable energy research. The vacant 4f orbitals of rare earth elements, which serve as capturing centers to prevent the recombination of generated charges, make them more affordable replacements than noble metals. In this study, we synthesized novel samarium aluminium sulphide and graphitic carbon nitride (SmAlS 3 /g-C 3 N 4 ) nanocomposite as an electrocatalyst by using the hydrothermal method. Designed in view of using in alkaline electrochemical water splitting, the resultant nanocomposite SmAlS 3 /g-C 3 N 4 was characterized using scanning electron microscopy and X-ray diffraction to confirm its distinct size, crystallinity and shape. Based on our investigations, the nanocomposite SmAlS 3 /g-C 3 N 4 performed better than its pristine components SmAlS 3 and g-C 3 N 4 . To attain 10 mA cm −2 current density, the SmAlS 3 /g-C 3 N 4 nanocomposite exhibited improved electrocatalytic efficiencies, obtaining low overpotentials 278 mV with 49 mV dec − ¹ Tafel slope for OER and 305 mV with 63 mV dec − ¹ Tafel slope for HER. The electrocatalyst SmAlS 3 /g-C 3 N 4 achieved overall water splitting current density of 10 mA cm −2 at an applied potential of 1.61 V. The produced SmAlS 3 /g-C 3 N 4 electrocatalyst exhibited notable robustness in the HER and OER procedures due to the eletronic interactions between SmAlS 3 and g-C 3 N 4 . This work provides a comprehensive understanding of the electrochemical process underlying the nanocomposite's performance in this specific setting, as well as a cogent method for applying innovative SmAlS 3 /g-C 3 N 4 nanocomposite system for energy-related research. • The samarium’s empty 4f orbitals are capturing centers, bars charge recombination. • The incorporation of SmAlS 3 on g-C 3 N 4 nanosheets increases its surface area. • The synthesized nanocomposite SmAlS 3 /g-C 3 N 4 showed narrowed band gap (2.23 eV). • The SmAlS 3 /g-C 3 N 4 showed strong electrocatalytic endurance and long-term stability.