A pair to fret about: Biotinylated phosphor nanoparticles that emit upconversion luminescence have been taken with biotinylated Au nanoparticles, which act as energy acceptors, and the pair has been applied to the determination of trace amounts of avidin based on fluorescence resonant energy transfer (FRET; see picture).

Green upconversion emission from hexagonal‐phase NaYF4:Yb, Er3+ phosphors can be directly observed with the naked eye. Powders with controlled size and morphology can be synthesized in ethanol and show a minimal decrease in luminescence intensity after 24 h (see Figure). The intense upconversion emission suggests good crystallinity of the materials, which may be used in biological labeling.

The formation process of CdS nanorods prepared by the reaction of thiourea and cadmium nitrate in ethylenediamine was investigated in detail by X-ray powder diffraction, transmission electron microscopy, selected-area electron diffraction, and IR techniques. An accordion-like folding process was proposed to account for the formation of CdS nanorods. Further studies indicate that the dissociation of ethylenediamine molecule adsorbed on the surface of CdS results in the formation of CdS nanorods. The obtained CdS single-crystal nanorods showed an abnormal electron diffraction that was explained by the double diffraction of the incident electron inside the sample. The result from electron diffraction confirmed that CdS nanorods grew along c axis.

Thin single‐crystal tellurium nanobelts and nanotubes have been created by the hydrothermal disproportionation of Na2TeO3 in aqueous ammonia solution, without the presence of any catalysts or templates. It appears that tellurium nanobelts with a helical pitch can be coaxed into chiral nanotubes under these conditions, presenting the promise of a new nanotube synthesis route (see Figure).

Ultrathin transition-metal-based nanomeshes can perfectly combine the advantages of two-dimensional (2D) ultrathin nanosheets and porous nanostructures, which have wide applications in energy storage and conversion. In this work, we present an etch-free one-step approach to directly synthesize the ultrathin Co 3 O 4 nanomeshes (Co-UNMs) by employing a CoCl 2 /K 3 Co(CN) 6 cyanogel as the reaction precursor. The 2D planar structural unit and solid properties of the cyanogel result in the preferential assembly of generated crystal nuclei at the solid−liquid interface (i.e., cyanogel−solution interface) in the 2D direction, which plays a key role in the formation of nanomeshes. The as-prepared Co-UNMs with 1.5 nm thickness and abundant pores have high surface area and numerous defect atoms, resulting in enhanced activity for the oxygen evolution reaction (OER) in alkaline media, such as a low overpotential of 307 mV at 10 mA cm −2 , a small Tafel slope of 76 mV dec −1 , and attractive durability in 1 M KOH electrolyte.

Atomically ultrathin rhodium nanosheets obtained by the cyanogel reduction method demonstrate an excellent electrocatalytic activity for the nitrogen reduction reaction.

Poly(thiophene) as a kind of n-doped conjugated polymer with reversible redox behavior can be employed as anode material for lithium-ion batteries (LIBs). However, the low redox activity and poor rate performance for the poly(thiophene)-based anodes limit its further development. Herein, a structure-design strategy is reported for thiophene-containing conjugated microporous polymers (CMPs) with extraordinary electrochemical performance as anode materials in LIBs. The comparative study on the electrochemical performance of the structure-designed thiophene-containing CMPs reveals that high redox-active thiophene content, highly crosslinked porous structure, and improved surface area play significant roles for enhancing electrochemical performances of the resulting CMPs. The all-thiophenebased polymer of poly(3,3′-bithiophene) with crosslinked structure and a high surface area of 696 m 2 g −1 exhibits a discharge capacity of as high as 1215 mAh g −1 at 45 mA g −1 , excellent rate capability, and outstanding cycling stability with a capacity retention of 663 mAh g −1 at 500 mA g −1 after 1000 cycles. The structure-performance relationships revealed in this work offer a fundamental understanding in the rational design of CMPs anode materials for high performance LIBs.

The conduction band energy, conductivity, mobility, and electronic trap states of electron transport layer (ETL) are very important to the efficiency and stability of a planar perovskite solar cell (PSC). However, as the most widely used ETL, TiO often needs to be prepared under high temperature and has unfavorable electrical properties such as low conductivity and high electronic trap states. Modifications such as elemental doping are effective methods for improving the electrical properties of TiO and the performance of PSCs. In this study, Nb-doped TiO films are prepared by a facile one-port chemical bath process at low temperature (70 °C) and applied as a high quality ETL for planar PSCs. Compared with pure TiO, the Nb-doped TiO is more efficient for photogenerated electron injection and extraction, showing higher conductivity, higher mobility, and lower trap-state density. A PSC with 1% Nb-doped TiO yielded a power conversion efficiency of more than 19%, with about 90% of its initial efficiency remaining after storing for 1200 h in air or annealing at 80 °C for 20 h in a glovebox.