Insights into different dimensional MXenes for photocatalysis

Introducing cocatalyst is one of the effective strategies to improve the photocatalytic performance of semiconductors. Noble metals are often used as cocatalysts for photocatalysis, while high cost significantly limits their commercial application on large scale. As novel transition metal carbides and nitrides, MXenes have emerged as a good alternate for improving photocatalytic performance in renewable energy and environmental remediation fields due to their high surface area, adjustability of elemental composition and suitable Fermi level. Many theoretical and experimental studies suggest that the performance of MXenes critically rely on their dimensions. Therefore, understanding the current state of art of different dimensional MXenes in photocatalysis is essential to clarifying the development of the prospects. This review summarizes the recent synthesis and applications of different dimensional MXene-based photocatalysts in the fields of hydrogen generation, CO2 conversion and pollutant degradation/removal. Furthermore, the challenges and prospects of MXenes for photocatalysis are also discussed, which is expected to inspire rational engineering of different dimensional MXene-based photocatalysts toward target applications.