Design and fabrication of graphitic carbon nitride incorporated nickel selenide hybrid composite for effective degradation of organic pollutants under UV and natural sunlight irradiations

Abstract

Addressing the challenge of developing a visible-light-driven photocatalyst with robust redox capabilities for organic pollutant degradation in environmental remediation, this study presents a novel hybrid composite. The composite was synthesized using g-C3N4 and NiSe2 through an ultrasonication-assisted hydrothermal method. Notably, the energy gap of this hybrid composite decreased from 2.72 to 2.30 eV as the g-C3N4 concentration ranged from 0 wt% to 30 wt%, as per the Kubelka–Munk theory. The surface area of the hybrid composite stood out at 31.2 m2/g, surpassing pristine NiSe2 (18.9 m2/g) and g-C3N4 (15.2 m2/g), as confirmed by BET analysis. The photocatalytic prowess of NiSe2/g-C3N4 composites was systematically investigated for the degradation of Reactive Blue 5 (RB 5) and Reactive Violet 5 (RV 5). Notably, the compositions with 30 % g-C3N4 incorporated into NiSe2 exhibited the highest degradation rates (86.4 % for RB 5 and 89.4 % for RV 5) and rate constants (0.0093 min−1 for RB 5 and 0.0095 min−1 for RV 5) during the degradation processes. Furthermore, the incorporation of g-C3N4 into NiSe2 not only elevated the surface area but also improved the separation rate of photogenerated electrons and holes. This enhancement significantly enhanced the visible-light-driven photodegradation performance of RB 5 and RV 5. The study also proposes a mechanism to explain the impact of graphitic carbon nitride concentration on photocatalytic performance. This research contributes to the development of advanced photocatalysts for eco-friendly pollutant degradation and provides insights into their composition-performance relationships.