Au decorated chemically exfoliated g-C3N4 as highly efficient visible light catalyst for hydrogen production

Abstract

The demand for photocatalytic hydrogen production through water splitting is continuously increasing as the world is seeking cleaner and sustainable energy solutions. Herein, we report a comparative study of the as-fabricated Bulk g-C3N4 (BCN), chemically exfoliated g-C3N4 (ECN) and Au-decorated chemically exfoliated g-C3N4 (Au/ECN) photocatalysts for visible light-driven catalytic hydrogen production. To understand the structural, morphological, chemical, and electronic properties of the as-fabricated photocatalysts, XRD, TEM, Raman, PL, XPS, FTIR, UV and EPR analysis was performed. The as-prepared Au/ECN photocatalyst revealed exceptional visible light catalytic performance by producing 410 μmol·g−1 of hydrogen, which is 27.3- and 9.3-fold enhanced compared to those of the CN (15 μmol·g−1) and ECN (44 μmol·g−1) photocatalysts, respectively. This improved visible light-driven catalytic performance of the Au/ECN photocatalyst for hydrogen production is due to the enhanced specific surface area via the chemically exfoliated layered sheets, promoted light absorption due to the decrease in band gap via the effect of surface plasmon resonance attributable to decorated Au nanoparticles, and efficient separation of charge carriers at the interfacial contact. The photocatalytic recyclable experiments indicate excellent stability of the Au/ECN photocatalyst for H2 evolution. These findings reveal the effect of chemical exfoliation and Au decorating on the catalytic efficiency of g-C3N4-based photocatalysts, revealing potential functions for green hydrogen production under the standard visible light illumination.