Insight into the bactericidal mechanisms of g-C3N4-based metal and metallic-compound junctions: A review
The use of sunlight to inactivate bacteria through photocatalysis is crucial for a sustainable future. Bactericidal performance is closely related to the charge dynamics of semiconductors. Among various semiconductors, graphitic carbon nitride (g-C3N4) has emerged as an attractive candidate for photocatalytic sterilization due to its chemical stability and versatility as a platform for constructing composites. However, the visible-light absorption and charge-separation performance of pristine g-C3N4 are insufficient, which limits further improvement in its bactericidal performance. Constructing g-C3N4-based metal or metallic-compound junctions has been shown to improve charge dynamics, including the introduction of plasma with surface plasmon resonance effect to photocatalysis and the construction of g-C3N4-based Schottky junctions. In this review, we first outline the basic principles of photocatalytic sterilization and then discuss the close relationship between bactericidal performance and the energy-band structure of semiconductors. We next summarize the factors limiting the performance of pristine g-C3N4, review common strategies for improving its bactericidal activity, and explain the underlying mechanisms. Finally, we discuss the remaining challenges and potential strategies to improve the practical applicability of g-C3N4-based metal and metallic-compound junctions.

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