Self-assembled carbon nitride sphere/sheet heterostructure for enhanced photocatalytic hydrogen generation

• Main Author: Soh, Zhen Yao
• Other Authors: Xue Can
• Format: Final Year Project
• Language: English
• Published: 2017
• Subjects: DRNTU::Engineering::Materials
• Online Access: http://hdl.handle.net/10356/69945
• Institution: Nanyang Technological University

The consumption of fossil fuels as our daily energy source is not only depleting this non-renewable resource of energy and it also threatens our planet due to the production of greenhouse gases which brings about global warming. Many scientists have tried to harvest hydrogen, which is an alternative clean fuel through the use of photocatalytic water splitting. However, a highly efficient photocatalyst has yet to be developed despite decades of research and we are still looking for various ways to enhance the photocatalytic efficiency of such catalysts. One very attractive photocatalyst is g-C3N4, as it can be fabricated from earth-abundant materials and possesses a relatively low band gap. Unfortunately, it has poor photocatalytic performance due to high charge recombination, hence we aim to enhance the photocatalytic efficiency of g-C3N4 in this study. In this study we fabricated C3N4 microspheres, C3N4 nanosheets and the C3N4-microsphere/nanosheet heterostructure hybrids. The heterostructure catalysts were constructed by the electro-assembly of C3N4 nanosheets and microspheres to form a core-shell structure. The photocatalysts were characterised using scanning electron microscopy (SEM) and UV-Vis spectroscopy. Data obtained from the photocatalytic water splitting experiments showed that the heterostructure hybrids generally produced more H2 than their constituents. The experiments proved the fact that such heterostructure photocatalysts have enhanced charge separation and increased surface area for reaction.