Graphitic Carbon Nitride (g-C₃N₄)-Based Nanocomposites for Artificial Photosynthesis toward Renewable Energy Production

In this 21^st century, the exploration of renewable energy to replace the traditional fossil fuels is of scientific significance. Amid the available renewable energy techniques, the utilization of clean solar energy for artificial photosynthesis is regarded as one of the auspicious strategies to combat the onslaught of climate change and surmount the contemporary descending resources of fossil fuels. In view of the massive potential of “solar + water/CO₂ → energy fuels”, photocatalysis has been categorized as the “Holy Grail” of modern photochemistry, which has underpinned incessant research fascination for the past few decades. Recently, graphitic carbon nitride (g-C₃N₄) has spurred a renaissance of interest in the realm of energy production due to its compelling properties such as its earth-abundant nature, non-toxicity and moderate band gap of around 2.7 eV with visible light activation.^1,2 In this talk, the state-of-the-art research advancement in our laboratory toward effective photocatalytic solar energy conversion (i.e. CO₂ reduction and H₂O splitting) using g-C₃N₄-based nanocomposites will be systematically presented. Various modification methods of pristine g-C₃N₄ will be discussed. This includes: the incorporation of metal-free carbonaceous nanomaterials (e.g. two-dimensional (2D) graphene^3,4 and zero-dimensional (0D) carbon nanodots⁵), the hybridization of another semiconductor photocatalyst,⁶ the coupling of transition metal phosphides (e.g. Ni₂P, Ni₁₂P₅ and Co₂P) and so forth. In short, the present studies open up a new invigorating prospect toward intelligent design of g-C₃N₄-based nanocomposites with ameliorated charge separation and migration in CO₂ reduction and water splitting, which can be extended to various energy-related applications such as solar cells, photovoltaics and electrocatalysis.