Themed collection Molecular Photoswitches for Energy storage


X-ray luminescent metal–organic frameworks: design strategies and functional applications
This review focuses on the design strategies, structure–function relationships, and recent advancements of MOF-based X-ray scintillators utilized in high-sensitivity and high-resolution X-ray detectors, flexible imaging, and X-ray radiation therapy.
J. Mater. Chem. C, 2025,13, 4836-4860
https://doi.org/10.1039/D4TC05299D
Tuning molecular assembly to enhance azobenzene-based solar thermal fuel efficiency
The intermolecular interactions of the photoswitches can be tuned by controlling the assembly of the photoswitches within the STF materials to achieve efficient STF materials.
J. Mater. Chem. C, 2025,13, 3167-3192
https://doi.org/10.1039/D4TC02993C
Manipulation of photoresponsive liquid-crystalline polymers and their applications: from nanoscale to macroscale
We summarize the molecular design of photoresponsive liquid-crystalline polymers, manipulation at multiple scales and various applications based on their intrinsic properties, providing an opportunity for future development in this field.
J. Mater. Chem. C, 2024,12, 10246-10266
https://doi.org/10.1039/D4TC02213K
Optimizing the performance of phase-change azobenzene: from trial and error to machine learning
Machine learning can predict the properties of phase change azobenzene derivatives and guide molecular design to further improve their photothermal conversion performance.
J. Mater. Chem. C, 2024,12, 3811-3837
https://doi.org/10.1039/D4TC00450G

Multichromophoric photoswitches for solar energy storage: from azobenzene to norbornadiene, and MOST things in between
In the context of energy storage, multichromophoric systems may offer additional functionality over monosubstituted analogues due to their potential to access multiple states as well as having more attractive physical properties.
J. Mater. Chem. A, 2024,12, 3180-3208
https://doi.org/10.1039/D3TA05972C

Multilayer films for photon upconversion-driven photoswitching
The use of triplet–triplet annihilation upconversion (TTA-UC) to drive photoswitching of the energy-storing norbornadiene–quadricyclane (NBD–QC) isomers in the solid-state is demonstrated.
J. Mater. Chem. C, 2024,12, 19030-19034
https://doi.org/10.1039/D4TC03513E

Exploring ortho-dianthrylbenzenes for molecular solar thermal energy storage
Aiming to explore anthracene-based systems for molecular solar thermal energy storage, five ortho-dianthrylbenzenes were designed, demonstrating promising properties for future development of anthracene-based photoswitches for such applications.
J. Mater. Chem. A, 2024,12, 26457-26464
https://doi.org/10.1039/D4TA03879G
Polythiophene-derived nickel cobaltite nanocomposites showing excellent photo-switching and photo-assisted enhanced supercapacitor properties
A solid-state photo-assisted supercapacitor from a polythiophene derivative and spinel NiCo2O4 exhibits a specific capacitance 106 F g−1, an increased rate capability of 10.6% and cyclic stability of 5% under UV-light compared to dark conditions.
J. Mater. Chem. A, 2025, Advance Article
https://doi.org/10.1039/D4TA09051A
High-performance organic thin-film phototransistors based on stacked p–n heterojunctions for enhanced optoelectronic response
We designed a tandem heterojunction with p- and n-type semiconductors to enhance exciton dissociation and transport, offering potential for optoelectronic advancements.
J. Mater. Chem. C, 2025,13, 2210-2218
https://doi.org/10.1039/D4TC04467C

Molecular insights into solid-state photochromism in bulk and confined N-salicylidenes
The structural basis for solid-state photochromism is uncovered for a model set of N-salicylidenes. Occlusion within a metal–organic frameworks imparts photochromic properties to N-salicylidenes that are non-photochromic in the bulk crystalline state.
J. Mater. Chem. C, 2024,12, 19453-19462
https://doi.org/10.1039/D4TC02862G
Ultra-wide temperature cycle control based on photo-responsive phase change
BN–PVA/Azo-OCn composite aerogels achieve relatively constant temperatures with low-temperature heat release and high-temperature heat absorption over an ultra-wide temperature range (−20 °C to 80 °C).
J. Mater. Chem. A, 2024,12, 28095-28106
https://doi.org/10.1039/D4TA04540H
Sunlight driven E–Z isomerization of liquid crystals based on hexahydroxytriphenylene nano-templates for enhanced solid-state solar thermal energy storage
Visible-light responsive liquid crystals based on hexahydroxytriphenylene nano-templates exhibiting efficient sunlight charging of up to 80% and a high heat release of ≈9 °C on discharging.
J. Mater. Chem. A, 2024,12, 27373-27380
https://doi.org/10.1039/D4TA05275G

Elucidating the mechanism of solid-state energy release from dianthracenes via auto-catalyzed cycloreversion
A mechanistic investigation of molecular solar thermal energy release by solid-state cycloreversion of dianthracenes to anthracenes reveals the integral roles of chemical and physical transformations of molecules towards the total energy release.
J. Mater. Chem. A, 2024,12, 26678-26686
https://doi.org/10.1039/D4TA05282J
Visible light activated dendrimers for solar thermal energy storage and release below 0 °C
Molecular solar thermal (MOST) fuels offer a closed-cycle and renewable energy storage strategy that can harvest photons within the chemical conformations and release heat on demand through reversible isomerization of molecular photoswitches.
J. Mater. Chem. A, 2024,12, 23723-23731
https://doi.org/10.1039/D4TA04022H
Phase-pure Ruddlesden–Popper tin halide perovskites for solar energy conversion applications
Solvophobic engineering strategy promotes the self-assembly of fluorinated cations into micelles, which changes the crystallization mode and thus leads to the formation of phase-pure Ruddlesden–Popper tin halide perovskites.
J. Mater. Chem. A, 2024,12, 21008-21015
https://doi.org/10.1039/D4TA02405B
About this collection
The necessity to harvest and store energy is one of the greatest challenges of today. The sun represents in this respect the ultimate energy source on earth. The utilization of light as energy input is therefore highly desirable. Molecular photoswitches do exactly that, as they can be switched between two states. Such processes have great potential in energy storage. This special issue celebrates results in all areas covering molecular photoswitches in the broadest sense for energy storage.
This Journal of Materials Chemistry A and Journal of Materials Chemistry C themed collection is Guest Edited by Professor Rachel Evans (0000-0003-2956-4857, University of Cambridge, UK), Professor Grace Han (0000-0002-2918-1584, Brandeis University, USA), Professor Tao Li (0000-0002-2410-0175, Shanghai Jiao Tong University, China) and Professor Dr Hermann A. Wegner (0000-0001-7260-6018, Justus-Liebig Universität, Germany). We hope that this collection will give readers an overview of some of the most recent work concerning molecular photoswitches for energy storage and will help to promote exciting research in the field.