Controlling the Shape Anisotropy of Monoclinic NbO Nanocrystals Enables Tunable Electrochromic Spectral Range.

Electrochromic smart windows that modulate the solar transmittance in a wide and selective spectral range can optimize building energy efficiency. However, for conventional materials such as bulk transition metal oxides, the electrochromic spectral range is constrained by their crystal structure with limited tunability. Herein, we report a method to control the shape anisotropy of monoclinic NbO nanocrystals and obtain a tunable electrochromic spectral range.

Synthesis and Dual-Mode Electrochromism of Anisotropic Monoclinic NbO Colloidal Nanoplatelets.

Transition metal oxide nanocrystals with dual-mode electrochromism hold promise for smart windows enabling spectrally selective solar modulation. We have developed the colloidal synthesis of anisotropic monoclinic NbO nanoplatelets (NPLs) to investigate the dual-mode electrochromism of niobium oxide nanocrystals. The precursor for synthesizing NPLs was prepared by mixing NbCl and oleic acid to form a complex that was subsequently heated to form an oxide-like structure capped by oleic acid, denoted as niobium oxo cluster.

Colloidal ReO Nanocrystals: Extra Re d-Electron Instigating a Plasmonic Response.

Rhenium (+6) oxide (ReO) is metallic in nature, which means it can sustain localized surface plasmon resonance (LSPR) in its nanocrystalline form. Herein, we describe the colloidal synthesis of nanocrystals (NCs) of this compound, through a hot-injection route entailing the reduction of rhenium (+7) oxide with a long chain ether. This synthetic protocol is fundamentally different from the more widely employed nucleophilic lysing of metal alkylcarboxylates for other metal oxide NCs.

Achieving Low-Energy Driven Viologens-Based Electrochromic Devices Utilizing Polymeric Ionic Liquids.

Herein, three kinds of viologens-based electrochromic devices (ECDs) (heptyl viologen (HV(BF)), octyl viologen (OV(BF)), and nonyl viologen (NV(BF))) were fabricated utilizing ferrocene (Fc) as a redox mediator. Among them, the NV(BF)-based ECD exhibits the highest coloration efficiency (36.2 cm/C) owing to the lowest driving energy.

Thermally Cured Dual Functional Viologen-Based All-in-One Electrochromic Devices with Panchromatic Modulation.

Vinyl benzyl viologen (VBV) was synthesized and utilized to obtain all-in-one thermally cured electrochromic devices (ECDs). The vinyl moiety of VBV monomer could react with methyl methacrylate (MMA) to yield bulky VBV/poly(methyl methacrylate) (PMMA) chains and even cross-linked network without the assistance of additional cross-linker. Both the bulky VBV/PMMA chains and the resulting polymer network can hinder the aggregation of the viologens and reduce the possibility of dimerization, rendering enhanced cycling stability.

Planar Heterojunction Perovskite Solar Cells Incorporating Metal-Organic Framework Nanocrystals.

Zr-based porphyrin metal-organic framework (MOF-525) nanocrystals with a crystal size of about 140 nm are synthesized and incorporated into perovskite solar cells. The morphology and crystallinity of the perovskite thin film are enhanced since the micropores of MOF-525 allow the crystallization of perovskite to occur inside; this observation results in a higher cell efficiency of the obtained MOF/perovskite solar cell.