A highly dispersible and stable nanocomposite of Cu(tpa)-GO (Cu(tpa) = copper terephthalate metal-organic framework, GO = graphene oxide) was prepared through a simple ultrasonication method. The morphology and structure of the obtained composite were characterized via scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis, Fourier-transform infrared (FT-IR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). On the basis of the characterization results, the binding mechanism of the Cu(tpa) and GO was speculated to be the cooperative interaction of π-π stacking, hydrogen bonding, and Cu-O coordination. The electrochemical sensing property of Cu(tpa)-GO composite was investigated through casting the composite on a glassy carbon electrode (GCE), followed by an electro-reduction treatment to transfer the GO in the composite to the highly conductive reduced form (electrochemically reduced graphene, EGR). The results demonstrated that the electrochemical signals and peak profiles of the two drugs of acetaminophen (ACOP) and dopamine (DA) were significantly improved by the modified material, owing to the synergistic effect from high conductivity of EGR and unique electron mediating action of Cu(tpa). Under the optimum conditions, the oxidation peak currents of ACOP and DA were linearly correlated to their concentrations in the ranges of 1-100 and 1-50 μM, respectively. The detection limits for ACOP and DA were estimated to be as low as 0.36 and 0.21 μM, respectively.

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Ce3+ and Mn2+ co-doped normalBa2Ca(BnormalO3)2 phosphors have been prepared at 950°C under a reduced atmosphere, and their luminescence properties have also been investigated by tuning the concentration of activators. White light-emitting phosphors excited with UV or violet light could be obtained in Ce3+ and Mn2+ coactivated normalBa2Ca(BnormalO3)2 phosphors by adjusting Mn2+ contents appropriately. Two types of Ce3+ centers, occupying the normalBa2+[Ce3+(1)] and normalCa2+[Ce3+(2)] sites, respectively, emit blue and green light, whereas the Mn2+ enters the Ca2+ sites and emits red light. The energy transfer involving normalCe3+(1)→normalCe3+(2) , normalCe3+(1)→normalMn2+ , and normalCe3+(2)→normalMn2+ have also been observed by analyzing their photoluminescence (PL) and PL excitation spectra. The energy transfer efficiencies from different Ce3+ sites to Mn2+ were calculated by decline and growth of their emission relative intensity. In light of the principle of energy transfer and appropriate tuning of activator contents, we demonstrated that normalBa2Ca(BnormalO3)2 : Ce3+ , Mn2+ is potentially useful as an UV or near-UV convertible phosphor for white light–emitting diodes. Moreover, their CIE chromaticity coordinates, color temperature, and color-rendering index Ra have also been calculated according to corresponding PL spectra under 345 and 395nm radiation.

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A facile and scalable solution-based, spray pyrolysis synthesis technique was used to synthesize individual carbon nanospheres with specific surface area (SSA) up to 1106 m(2)/g using a novel metal-salt catalyzed reaction. The carbon nanosphere diameters were tunable from 10 nm to several micrometers by varying the precursor concentrations. Solid, hollow, and porous carbon nanospheres were achieved by simply varying the ratio of catalyst and carbon source without using any templates. These hollow carbon nanospheres showed adsorption of to 300 mg of dye per gram of carbon, which is more than 15 times higher than that observed for conventional carbon black particles. When evaluated as supercapacitor electrode materials, specific capacitances of up to 112 F/g at a current density of 0.1 A/g were observed, with no capacitance loss after 20,000 cycles.

Cesium‐lead‐halide perovskite quantum dots (PQDs), which have superior optical and electronic properties, are regarded as excellent materials for various optoelectronic devices. However, their unstable nature greatly hinders their practical application. Herein, a simple hydrolysis encapsulation method is developed to embed PQDs into mesoporous polystyrene microspheres (MPMs) followed by a silica shell covering process, which generates luminescent PQDs/MPMs@SiO2 hybrid microspheres with significantly enhanced stability. The obtained CsPbBr3‐PQDs/MPMs@SiO2 hybrid microspheres show a high photoluminescence quantum yield of 84%. More importantly, the MPMs@silica protective shells effectively cut off direct contact between outer erosive species and the inner embedded PQDs and modify the hybrid microspheres with ultralong alkyl chains for improved resistance to solvents and heat. Hence, these CsPbBr3‐PQDs/MPMs@SiO2 hybrid microspheres exhibit good chemical/physical stabilities, even when exposed to harsh environments, such as deionized water, isopropanol, acid/alkali solution, anion‐exchange reactions, and heating. Particularly, the water stability, which produced the remaining ≈48% proportion of the initial fluorescence intensity after a quite long aqueous storage period of 30 d, is the best reported among the stability‐related studies of PQDs. Meanwhile, white light‐emitting diodes (LEDs) are achieved by mixing green CsPbBr3‐PQDs/MPMs@SiO2 microspheres with red commercial phosphors on a blue chip. High power efficiency of 81 lm W−1 and good electroluminescence stability are obtained.

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