Construction novel highly active photocatalytic H2 evolution over noble-metal-free trifunctional Cu3P/CdS nanosphere decorated g-C3N4 nanosheet.

Hydrogen energy possesses immense potential in developing a green renewable energy system. However, a significant problem still exists in improving the photocatalytic H 2 production activity of metal-free graphitic carbon nitride (g-C 3 N 4) based photocatalysts. Here is a novel Cu 3 P/CdS/g-C 3 N 4 ternary nanocomposite for increasing photocatalytic H 2 evolution activity. In this study, systematic characterizations have been carried out using techniques like X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM), Raman spectra, UV–Vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy (XPS), surface area analysis (BET), electrochemical impedance (EIS), and transient photocurrent response measurements. Surprisingly, the improved 3CP/Cd-6.25CN photocatalyst displays a high H 2 evolution rate of 125721 μmol h−1 g−1. The value obtained exceeds pristine g-C 3 N 4 and Cu 3 P/CdS by 339.8 and 7.6 times, respectively. This could be the maximum rate of hydrogen generation for a g–C 3 N 4 –based ternary nanocomposite ever seen when exposed to whole solar spectrum and visible light (λ > 420 nm). This research provides fresh perspectives on the rational manufacture of metal-free g-C 3 N 4 based photocatalysts that will increase the conversion of solar energy. By reusing the used 3CP/Cd/g-C 3 N 4 photocatalyst in five consecutive runs, the stability of the catalyst was investigated, and their individual activity in the H 2 production activity was assessed. To comprehend the reaction mechanisms and emphasise the value of synergy between the three components, several comparison systems are built. Sphere-like Cu 3 P/CdS/g-C 3 N 4 photocatalyst was developed using hydrothermal route followed by ball milling and wet impregnation assisted method. A highest hydrogen production of 125721 μmol h−1g−1 was obtained for the above nanocomposite containing 6.25 wt% of g-C 3 N 4. [Display omitted] • Sphere-like Cu 3 P/CdS/g-C 3 N 4 composites was developed for visible light activity. • Metal free composites for H 2 evolution under visible light illumination was achieved. • The improved charge separation, transfer and transport results highest H 2 production. • Best activity results are observed for 3CP/Cd-6.25CN catalysts supported on g-C 3 N 4. • First time we report highest H 2 production activity for Cu 3 P/CdS/g-C 3 N 4 composites. [ABSTRACT FROM AUTHOR]