Unveiling cutting-edge progress in the fundamentals of MXene: Synthesis strategies, energy and bio-environmental applications

Currently the world is facing a web of challenges, of which the most important are, energy crisis, environmental pollution and health issues, worsened by the consumption of fossil fuels, various industries toxic effluents and noxious microbes. To address these thorny issues, a holistic approach is essential, emphasizing sustainable and renewable energy sources, water pollution and microbial control measures. Photo- and electro-catalysis have emerged as promising strategies, which could efficiently present a practical solution to these evils. These strategies dominate over the others due to their opto-electrical, physicochemical, green, economical, versatile, efficient, environmental-friendly and easy manipulation properties. Conventional semiconductor photocatalysts have limitations, e.g., wide bandgap, rapid recombination of charge carriers, non-selectivity and stability. However, cocatalysts coupling with semiconductor materials could compensate and overcome these challenges. Among two-dimensional (2D) cocatalysts, MXene have revealed huge potential owing to their unique properties which facilitate them as a wonderful material for their extensive applications. In this review, various innovative strategies for MXene synthesis have been explored in detail, including fluorine-based and fluorine-free approaches. Moreover, a comprehensive approach has been applied to deeply discuss the etching mechanisms, surface termination controlling, intercalation and delamination mechanisms of MXenes. The toxicity and promising antimicrobial properties of MXene are also discussed in this review. MXenes exhibits a multifaceted role in energy applications, showing its potential in clean and sustainable energy technologies, environmental remediation and biomedical sectors. Lastly, we conclude with current trends, challenges and possible future perspectives, offering valuable insights for researchers in multiple disciplines.