Molecular photoswitches for energy storage

In recent years, the quest for sustainable and efficient energy storage solutions has become increasingly urgent, driven by the need to address climate change and reduce our dependence on fossil fuels. Among the various innovative approaches being explored, molecular photoswitches have emerged as a promising frontier in this field. These remarkable compounds have the ability to switch between different states upon exposure to light, offering unique opportunities for energy storage and conversion.

This themed collection is dedicated to exploring the potential of molecular photoswitches for energy storage. It brings together contributions from leading researchers who are at the forefront of this exciting area, showcasing a diverse array of reviews and studies that illuminate both the fundamental science and practical applications of these versatile molecules.

Reviews and computational approaches

Liang et al. provide strategies for designing photoswitchable materials using X-ray luminescent metal–organic frameworks for energy storage applications (https://doi.org/10.1039/D4TC05299D).

Sahu et al. summarize recent developments in azobenzene-based solar thermal fuels, highlighting the interplay between molecular design and energy performance (https://doi.org/10.1039/D4TC02993C).

Wang et al. review machine learning tools for optimizing phase-change azobenzene materials, offering a computational framework for performance prediction (https://doi.org/10.1039/D4TC00450G).

Salthouse et al. explore multichromic photoswitches, describing how multiple switching pathways can yield multifunctional molecular devices (https://doi.org/10.1039/D3TA05972C).

Solid-state molecular solar thermal energy storage

Baggi et al. investigate ortho-dianthrylbenzenes as solid-state molecular solar thermal energy storage materials with enhanced switching capacity (https://doi.org/10.1039/D4TA03879G).

Raju et al. elucidate the solid-state energy release mechanism of dianthracenes, revealing a cooperative autocatalytic cycloreversion and a transient intermediate phase (https://doi.org/10.1039/D4TA05282J).

Wang et al. utilize triplet–triplet annihilation upconversion (TTA-UC) to enable visible-light-triggered photoswitching of norbornadiene–quadricyclane systems in solid-state multilayer films (https://doi.org/10.1039/D4TC03513E).

Liquid crystalline and elastomeric systems

Ji et al. review photoresponsive liquid-crystalline polymers, highlighting molecular design strategies and energy storage potential (https://doi.org/10.1039/D4TC02213K).

Gupta et al. demonstrate E–Z isomerization of hexahydroxytriphenylene-based liquid crystals under sunlight, achieving 1.87% solar conversion efficiency and 9.64 °C heat release (https://doi.org/10.1039/D4TA05275G).

Campos et al. incorporate photoswitches into liquid crystal elastomers via Diels–Alder chemistry, enabling mechanically active materials for photothermal applications (https://doi.org/10.1039/D5TA01043H).

Hybrid and composite materials

Griffiths et al. study solid-state photochromism in bulk and confined N-salicylidenes, providing insights into the interplay between structure and switching dynamics (https://doi.org/10.1039/D4TC02862G).

Ge et al. design a boron nitride–polyvinyl alcohol aerogel composite integrated with photo-responsive phase-change materials, showing enhanced light-triggered energy storage properties (https://doi.org/10.1039/D4TA04540H).

Alternative photoactive compounds

Pan et al. report phase-pure Ruddlesden–Popper tin halide perovskites, offering a new class of materials for photothermal energy conversion (https://doi.org/10.1039/D4TA02405B).

Xu et al. develop visible-light-activated dendrimers based on fluorochloroazobenzene, achieving high energy density and long storage lifetime under subzero conditions (https://doi.org/10.1039/D4TA04022H).

Device-oriented and functional materials

Basak et al. present polythiophene-derived nickel cobaltite nanocomposites with strong photo-switching behavior and enhanced supercapacitor performance under UV-light activation (https://doi.org/10.1039/D4TA09051A).

Fang et al. construct high-performance organic phototransistors based on p–n heterojunctions, demonstrating amplified optoelectronic response through tailored molecular stacking (https://doi.org/10.1039/D4TC04467C).

The field of molecular photoswitches for energy storage is still in its nascent stages, but the groundwork laid by these contributions is already pointing toward a bright future. As research continues to advance, we can anticipate significant breakthroughs that will bring us closer to realizing efficient and eco-friendly energy solutions.

This themed issue serves as both a testament to the progress made in the field of molecular photoswitches for energy storage and an inspiration for future endeavors. We extend our gratitude to all the contributors who have shared their insights and innovations, and we hope that this collection will stimulate further research and collaboration within this exciting domain.

Together, let us continue to push the boundaries of what is possible in energy storage, harnessing the power of molecular photoswitches to create a more sustainable world for future generations.

Acknowledgements

Dr Tao Li acknowledges the support of the National Natural Science Foundation of China (grant number: 22375123) and Dr Hermann Wegner acknowledges the support of the Deutsche Forschungsgemeinschaft (DFG) within the Research Unit FOR 5499 “Molecular Solar Energy Management – Chemistry of MOST Systems”.

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