Synergistic effect of Fe₂VO₄ and g-PTAP for efficient photoelectrochemical water oxidation

Individual photocatalyst materials' thermodynamic constraints pose a significant obstacle to obtaining efficient overall water splitting. Usually, a two-component ‘Z-scheme’ photocatalyst system is adopted to address this issue. In this regard, the present study reports the development of a novel Z-scheme heterostructure photocatalyst, Fe₂VO₄/graphitic-polytriaminopyrimidine (g-PTAP), for efficient solar-driven hydrogen production. Structural, morphological, and compositional analyses confirmed the successful integration of g-PTAP into the Fe₂VO₄ matrix, forming a hierarchical heterostructure. The heterostructure exhibited exceptional visible light absorption and reduced charge carrier recombination, leading to enhanced photoelectrochemical water oxidation performance. The superior photocatalytic hydrogen production activity of the Z-scheme heterostructure was attributed to the improved light harvesting, efficient charge separation, and transport facilitated by the synergistic interactions between Fe₂VO₄ and g-PTAP. The incorporation of g-PTAP lowers the onset potential from 0.8 V (for Fe₂O₄) to 0.6 V vs. reference electrode. As a result, the maximum current density was found to have increased fivefold (0.15 mA cm⁻²). The findings of this study provide valuable insights into the design of advanced Z-scheme heterostructure photocatalysts for sustainable solar fuel generation.