Exploring the principles and applications of non-metal photothermal catalysts: Insights from mechanistic differences with metal counterparts

Abstract

Photothermal catalysts can effectively harness the near-infrared (NIR) spectrum of sunlight to facilitate non-radiative relaxation and exhibit significant potential in environmental and energy-related applications. However, the photothermal performance of metal-based catalysts is hindered by the narrow bandwidth of their metal plasma resonance and the high material costs. Consequently, researchers are actively investigating new non-metal photothermal catalysts that offer simplified fabrication and operation. Non-metal photothermal catalysts include carbon-based photothermal catalysts and organic photothermal catalysts. In recent years, considerable attention has been dedicated to pursuing innovative and high-performance photothermal catalysts. Therefore, this review explores the differences in photothermal catalysis mechanisms between metal and non-metal photothermal catalysts, focusing explicitly on the development of carbon-based and donor–acceptor organic photothermal catalysts. It includes the thermal aggregation effect of carbon-based materials, twisted intramolecular charge transfer (TICT) effect, aggregation induction effect, and organic conjugation effect of organic photothermal catalysts. In addition, this review encompasses utilizing non-metal photothermal catalysts in diverse applications such as seawater resource utilization, carbon dioxide (CO₂) conversion, pollutant degradation, and photothermal therapy. In short, this review endeavors to provide researchers with an in-depth and holistic perspective on non-metal photothermal catalysts and broaden the application range for non-metal photothermal catalysts within the energy and environmental science fields.