Bio-inspired SiO2-hard-template reconstructed g-C3N4 nanosheets for enhanced photocatalytic hydrogen evolution

Abstract

Building architectures to manipulate light propagation using a light-conversion matrix is one of the most competitive strategies to enhance photocatalytic performance. In this work, a bio-inspired SiO₂ hard template with interconnected SiO₂ with a one-dimensional structure was devised to enhance the visible light harvesting ability of g-C₃N₄, and the SiO₂/g-C₃N₄ nanocomposite is cleverly synthesized via an in situ thermal polymerization method. Based on UV-vis diffuse reflectance spectrometry (UV-vis DRS) and finite difference time domain simulation (FDTD) measurements, it is found that the SiO₂/g-C₃N₄ nanocomposite displays obviously enhanced visible light absorption and light-scattering when compared to pristine g-C₃N₄, suggesting it has highly enhanced light harvesting ability. As expected, SiO₂/g-C₃N₄ displays a remarkable enhancement in photocatalytic H₂ production when compared to bare g-C₃N₄. Such enhancement is attributed to the synergistic effect of g-C₃N₄ and SiO₂ hard template microstructures. The SiO₂ one-dimensional structure not only enhances light scattering to widen the visible-light absorption range and improve the utilization efficiency of solar energy, but it also increases the specific surface area of g-C₃N₄ by reducing its aperture size. This research has far-reaching implications for increasing the use of sunlight and improving the development of hydrogen energy.