Novel Graphitic Carbon Nitride/Co-B-P Nanocomposites with Significantly Enhance Visible-Light Photocatalytic Hydrogen Production from Water Splitting

As a promising metal-free photocatalyst for hydrogen (H2) production through water splitting under visible-light irradiation, graphitic carbon nitride (g-C3N4) photocatalysts decorated with CoBP was prepared via simple ultra sonification. This paper highlights the structures of the photocatalysts, their stability, rate of hydrogen evolution and the mechanism of charge transfer within the photocatalysts. The prepared C3N4/CoBP nanocomposite photocatalysts were characterized by using X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, scanning electron microscopy and UV–visible (UV–vis) diffuse reflectance spectroscopy. After detailed analysis, the C3N4/CoBP nanocomposite photocatalysts showed excellent photocatalytic performance, which was due to the formation of the heterostructured hybrids of g-C3N4 and CoBP. The effects of C3N4/CoBP nanohybrids on H2 evolution were evaluated. The effects improved with increasing load of CoBP until the optimal level (5 wt% CoBP with visible-light irradiation at λ ≥420 nm). The maximum and remarkable photocatalytic H2 evolution rate of 51.68 μmol h−1 was achieved, which was 3.8 times that obtained from pure g-C3N4. Moreover, the C3N4/CoBP heterostructured nanohybrids demonstrated extremely high photostability and recyclability for H2 evolution after visible light illumination. The composite hybrid accelerated the separation and transfer of photogenerated charge carriers and subsequently suppressed charge recombination. Conclusively, this study offered an opportunity for the design and synthesis of highly stable and efficient C3N4/CoBP nanocomposite photocatalysts for energy conversion and utilisation.