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Portable and wearable devices have attracted wide research attention due to their intimate relations with human daily life. As basic structures in the devices, the preparation of high-conductive metallic circuits or micro-circuits on flexible substrates should be facile, cost-effective, and easily integrated with other electronic units. In this work, high-conductive carbon/Ni composite structures were prepared by using a facile laser direct writing method, followed by an electroless Ni plating process, which exhibit a 3-order lower sheet resistance of less than 0.1 ohm/sq compared to original structures before plating, showing the potential for practical use. The carbon/Ni composite structures exhibited a certain flexibility and excellent anti-scratch property due to the tight deposition of Ni layers on carbon surfaces. On the basis of this approach, a wireless charging and storage device on a polyimide film was demonstrated by integrating an outer rectangle carbon/Ni composite coil for harvesting electromagnetic waves and an inner carbon micro-supercapacitor for energy storage, which can be fast charged wirelessly by a commercial wireless charger. Furthermore, a near-field communication (NFC) tag was prepared by combining a carbon/Ni composite coil for harvesting signals and a commercial IC chip for data storage, which can be used as an NFC tag for practical application.

The morphology engineering represents an alternative route toward efficient hematite photoanodes for photoelectrochemical (PEC) water splitting without changing the chemical composition. In this work, a facile and mild solvothermal synthesis of unique ferrihydrite branched nanosheet arrays vertically aligned on FTO substrate was achieved at around 100 °C. The hierarchical branched ferrihydrite nanosheet arrays consisted of tiny branches up to 40 nm in length grown almost vertically on stem nanosheets ∼10 nm in thickness. Moreover, the variation of the morphology of the ferrihydrite nanostructures from bare nanosheet arrays through branched nanosheet arrays to dense branched structures can be readily achieved through the regulation of the reaction time and temperature. The obtained ferrihydrite branched nanosheet arrays can be in situ transformed into α-Fe2O3nanosheet arrays with small surface protrusions upon annealing at 550 °C. After a simple postgrowth Ti-doping process, the resulting Ti-doped α-Fe2O3nanosheet arrays showed a good PEC performance for water splitting with a photocurrent density of 1.79 mA/cm2at 1.6 V vs RHE under AM 1.5G illumination (100 mW/cm2). In contrast, the Ti-doped irregular aggregates of the α-Fe2O3nanograins transformed from dense ferrihydrite branched structures exhibited a much lower photocurrent density (0.41 mA/cm2at 1.6 V vs RHE), demonstrating the important influence of the morphology of α-Fe2O3photoanodes on the PEC performance.

Reducing the reflection and improving the transmission or absorption of light from wide angles of incidence in a broad wavelength range are crucial for enhancing the performance of the optical, optoelectronic, and electro-optical devices. Inspired by the structures of the insect compound eyes, nanostructure arrays (NSAs) have been developed as effective antireflective surfaces, which exhibit promising broadband and quasi-omnidirectional antireflective properties together with multifunctions. This review summarizes the recent advances in the fabrication and performance of antireflective surfaces based on NSAs of a wide variety of materials including silicon and non-silicon materials. The applications of the NSA-based antireflective surfaces in solar cells, light emitting diodes, detection, and imaging are highlighted. The remaining challenges along with future trends in NSA-based antireflective surfaces are also discussed.

Mesocrystals, which are assemblies of crystallographically oriented nanocrystals, have received increasing attention due to their unique properties such as high crystallinity, high porosity, oriented subunit alignment, and similarity to highly sophisticated biominerals. However, the controlled synthesis of TiO2mesocrystals has not been realized until recently, probably because of the difficulty in accurately controlling the reaction processes that produce TiO2crystals. In this review, recent advances in the synthesis and applications of TiO2mesocrystals are summarized with particular attention paid to the mechanisms of their formation. Three typical pathways for the preparation of TiO2mesocrystals are discussed, namely topotactic transformation, direct synthesis in solution, and growth on supports. The potential applications of TiO2mesocrystals in lithium ion batteries, photocatalysis, enzyme immobilization, and antireflection materials are also described.Mesocrystals, which are assemblies of crystallographically oriented nanocrystals, have received increasing attention due to their unique properties such as high crystallinity, high porosity, oriented subunit alignment, and similarity to highly sophisticated biominerals. However, the controlled synthesis of TiO2mesocrystals has not been realized until recently, probably because of the difficulty in accurately controlling the reaction processes that produce TiO2crystals. In this review, recent advances in the synthesis and applications of TiO2mesocrystals are summarized with particular attention paid to the mechanisms of their formation. Three typical pathways for the preparation of TiO2mesocrystals are discussed, namely topotactic transformation, direct synthesis in solution, and growth on supports. The potential applications of TiO2mesocrystals in lithium ion batteries, photocatalysis, enzyme immobilization, and antireflection materials are also described.

Uniform anatase TiO2nanocuboids enclosed by active {100} and {001} facets over a wide size range (60–830 nm in length) with controllable aspect ratios were solvothermally synthesized through hydrolysis of titanium tetraisopropoxide (TTIP) using acetic acid (HAc) as the solvent and the ionic liquid 1‐butyl‐3‐methylimidazolium tetrafluoroborate ([bmim][BF4]) as the capping agent. The size and aspect ratio of the anatase TiO2nanocuboids can be readily adjusted by changing the composition parameters including the contents of [bmim][BF4], water, and HAc in the quaternary solution system. It was revealed that [bmim][BF4] played an important role in stabilizing both the {100} and {001} facets of the anatase TiO2nanocuboids. On the one hand, [bmim][BF4] acted as a fluoride source to release F−ions for stabilizing the {001} facets; on the other hand, the [bmim]+ions acted as effective capping ions to preferentially stabilize the {100} facets. The obtained near‐monodisperse anatase TiO2nanocuboids exhibited an interesting self‐assembly behavior during deposition. These single‐crystalline anatase nanocuboids showed extremely high crystalline phase stability, retaining the pure phase of anatase as well as the morphology even after being calcined at 900 °C. Moreover, the anatase nanocuboids exhibited considerably enhanced photocatalytic activity owing the wholly exposed active {100} and {001} facets.