Nanoarchitectonics of Two-Dimensional Materials for Photocatalysis: Design Strategies, Mechanistic Insights, and Application Pathways

Abstract

Photocatalysis has become a pivotal technology for solar-to-chemical energy conversion and environmental purification, yet its widespread implementation remains hindered by insufficient light harvesting, rapid electron–hole recombination, and limited accessibility of active sites. The emergence of two-dimensional (2D) materials—including graphene derivatives, transition-metal dichalcogenides, layered double hydroxides, g-C₃N₄, and MXenes—has opened new frontiers for overcoming these intrinsic bottlenecks. Owing to their atomic-level thickness, tunable electronic structure, large surface-to-volume ratio, and superior charge transport characteristics, 2D architectures provide a versatile platform for nanoarchitectonics-driven photocatalyst design. This review systematically examines the principles and strategies of nanoarchitectonics applied to 2D materials, covering controlled defect engineering, heteroatom doping, interfacial coupling, phase modulation, and hierarchical assembly. Mechanistic insights into charge separation pathways, band structure tailoring, surface redox kinetics, and synergistic effects arising from 2D–2D and 2D–3D hybrid systems are highlighted to elucidate how structural manipulation at the nanoscale governs photocatalytic behavior. Additionally, the article outlines key application pathways of engineered 2D photocatalysts in hydrogen evolution, CO₂ reduction, nitrogen fixation, and degradation of emerging pollutants, emphasizing the relationship between material architecture and functional performance. Finally, current challenges—including long-term stability, scalability of synthesis, environmental and toxicity considerations, and the need for operando characterization—are critically discussed. Perspectives for future research, such as integrating machine-learning-guided material discovery, multi-component nanoarchitectures, and sustainable fabrication routes, are proposed to guide the development of next-generation high-efficiency photocatalytic systems. Collectively, this review provides a comprehensive framework for understanding and advancing the nanoarchitectonics of 2D materials toward transformative photocatalytic technologies.