Engineering Low-Dimensional Materials for Efficient Energy Conversion

One-dimensional (1D) nanostructures, such as carbon dots, have gained significant attention due to their unique luminescent properties, high photostability, and excellent charge transport capabilities. These quasi-spherical nanoparticles, typically <10 nm in diameter, are valued for their ease of synthesis, versatile surface functionalization, strong light absorption, and high quantum yield. Such features make them promising for applications in photocatalysis, solar energy conversion, and optoelectronics. In photocatalytic systems, carbon dots enhance light harvesting, charge separation, and overall energy conversion efficiency. This review highlights recent progress in the synthesis, modification, and application of carbon dots for sustainable energy technologies. Two-dimensional (2D) materials offer exceptional electronic, optical, and mechanical properties, making them attractive for energy conversion applications. Their atomic thickness, large surface area, and tunable band structure enable efficient light–matter interactions and charge carrier transport, advancing photocatalysis, hydrogen evolution, and piezoelectric energy harvesting. In piezoelectric 2D materials such as Bi₂WO₆, WO₃ or MoS₂, mechanical deformation induces an internal electric field that promotes charge separation and reduces recombination, improving catalytic performance. 2D materials are also effective in sonocatalysis, where ultrasonic waves generate cavitation, producing localized high-energy conditions that activate catalyst surfaces, enhance mass transfer, and generate reactive species. Coupling light with ultrasound in sono-photocatalysis provides synergistic effects, enabling efficient pollutant degradation, water purification, and hydrogen production. Their incorporation into functional coatings and active membranes further improves selectivity, permeability, and durability, enabling multifunctional energy systems.

This review compares the advantages, challenges, and prospects of both 1D carbon-based nanostructures and 2D layered materials in next-generation sustainable energy technologies. The combined understanding of these material classes can guide future research, inspire hybrid designs, and accelerate the development of high-efficiency, cost-effective, and environmentally friendly energy solutions.

Acknowledgements

The European Commission grant supported this work: HORIZON-MSCA-2022-SE-01-01 – Piezo2D (project number 101131229) and H2020-MSCA-RISE-2018 - FUNCOAT (project number 823942)