Themed collection Nanomaterials for Energy Conversion and Storage

Guest editors Michael Grätzel and Kuppuswamy Kalyanasundaram introduce this Journal of Materials Chemistry themed issue on nanomaterials for energy conversion and storage.

High energy and eco-friendly supercapacitors are now accessible in aqueous medium through either redox reactions at the carbon–electrolyte interface or high over-potential for dihydrogen evolution.

This highlight reviews the recent researches and developments of graphene-based Schottky junction solar cells, including graphene-on-silicon Schottky junction solar cells, and graphene/ single nanowire (nanobelt) Schottky junction solar cells.

Significant progress in power conversion efficiencies and stabilities of polymer solar cells has been achieved using semiconducting metal oxides as charge extraction interlayers.

Our highlight describes the utmost important advances in the design and synthesis of ruthenium free sensitizers for efficient Grätzel solar cells.

Recent progress in understanding the origin of open-circuit voltage in OSCs is reviewed. Based on the model of DOS, disorder in donor–acceptor materials and bimolecular recombination are two main sources of open-circuit voltage loss.

Carbon dots for potential applications in photocatalysis, optoelectronics, sensor, SERS, and bio-imaging.

This review summarizes recent progress on both materials synthesis and self-assembly and lithography techniques toward ordered nanostructures and well-defined D/A interfaces that are expected to enhance the performance of organic solar cells.

This article presents water reduction by non-Pt metal nanoparticles and water oxidation by metal oxide nanoparticles prepared from metal complexes.

The degradation mechanisms of active layer materials are discussed and their protection from degradation are extensively discussed.

Graphene is becoming a potential alternative to indium tin oxide (ITO) for use as the electrode material in electronic devices.

We investigate the temperature and power dependence of the emission quantum yield of NaYF₄:Er,Yb upconverters. We demonstrate that formation of the hexagonal phase of this material is not in itself sufficient to guarantee high upconversion efficiency

An electrospun nest-shaped TiO₂ structure is used as a scattering layer on a P25 electrode for dye sensitized solar cells.

Control of processing parameters increases the stability of graphite–wax composites for thermal energy storage (stable system: right; unstable system: left).

The (de-)hydrogenation properties of La_1−zY_zH_x (z = 0, 0.4, 1) thin films during the dihydride–trihydride transition were investigated by means of hydrogenography.

A ZnO NW film with lower recombination centers has been developed, which demonstrates superior photovoltaic performance within a DSSC.

Bromine, azide, vinyl and oxetane were incorporated into the side chains of the polymer TQ1. Cross-linking of the polymers was achieved by UV-light illumination to give solvent resistant films and reduced growth of PCBM crystallites.

Tavorite and triplite are equally stable at ambient temperature but triplite is thermodynamically favored at high temperatures because of entropy.

An innovative solidified redox electrolyte for dye-sensitized solar cells (DSCs) was prepared by incorporating amorphous silica nanoparticles in a liquid system containing the Co²⁺/Co³⁺ shuttle dissolved in methoxypropionitrile. The incorporation of the solidified electrolyte in a DSC configuration resulted in an efficiency up to about 4% under 0.23 sun (AM 1.5G) illumination.

Novel electrolytes for high performance and stable dye sensitized solar cells.

Homogeneous VO₂ (B) nanorods approximately 100 nm in width and 1–2 μm in length have been fabricated via the hydrothermal process, and are then transformed into irregularly shaped V₂O₅ nanoparticles several hundreds of nanometers large and 20–30 nm thick after annealing the precursor material at 500 °C for 30 min.

An opportune mixing of PbS nanocrystals and a narrow band gap polymer led to hybrid solar cells with a broad spectral response and an efficiency of ∼3%.

Water dispersible graphene has been prepared by electrochemical exfoliation of graphite for energy storage electrode materials.

Non-fused ring building blocks of electron-rich quinoid structures have been used in low bandgap polymers for organic solar cells.

Semiconductor amphiphilic block copolymers, which form uniform micelles in water, were combined with inorganic semiconductor nanoparticles to create well defined donor–acceptor nanocomposites with domain sizes suitable for photovoltaic applications.

All-nanowire bulk heterojunction organic solar cells incorporating nanowires of oligothiophene-functionalized naphthalene diimide as electron acceptor and poly(3-hexylthiophene) nanowires as electron donor are demonstrated.

TiO₂ microspheres with adjustable morphologies and microstructures fabricated by a facile solvothermal process were evaluated for their reversible Li⁺ storage properties.

The conductivity of the composite membrane at 90 °C and 30% humidity was noted to be 54.6 mS cm⁻¹.

A “combinatorial” approach via the unidirectional solidification technique reveals the relationship between the composition, microstructure, and transport properties in a large compositional space.

A series of new highly efficient and stable dyes based on a quinacridone-containing furan moiety were designed and synthesized for dye-sensitized solar cells with an optimized overall conversion efficiency (η) of up to 7.70%.

The nanoscale morphology of proton conducting blend membranes is controlled by the architecture of the constituent ionomer.