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AgBiS2 has been considered by researchers as a new-generation photovoltaic material because of its ideal bandgap, environment-friendliness and wide absorption range. Although it has shown great development potential in solar cell devices, due to the lack of systematic exploration and research on precursor solution chemistry, the performance of AgBiS2 solar cells prepared by the precursor solution method lags behind those of colloidal solution–processed cells. Herein, we report a pre-nucleation strategy that involves controlling the precursor solution at the molecular level. The pre-nucleation strategy results in faster nucleation of the AgBiS2 crystals during crystallization, resulting in AgBiS2 thin films with larger grains, fewer defects and more homogeneous cation disorder. The improved quality of the AgBiS2 thin films resulted in high-performance AgBiS2 thin film solar cells with a JSC of up to 30.9 mA cm−2 and a record high PCE of 3.68%. This work provides a feasible method for the preparation of AgBiS2 thin film solar cells based on the precursor solution. [ABSTRACT FROM AUTHOR]

Established decarboxylative Minisci reactions are limited to aliphatic carboxylic acids, as their analogs, silanecarboxylic acids, have been rarely investigated. Herein, we present a new decarboxylative Minisci-type reaction of N-heteroarenes with silanecarboxylic acids under photo- or silver-mediated conditions. This C–H silylation strategy provides efficient access to diverse N-heteroarylsilanes in moderate to excellent yields with high regioselectivity, among which Ag-catalysed decarboxylation of silanecarboxylic acids furnishes an unprecedented method for silyl radical generation. [ABSTRACT FROM AUTHOR]

Prussian blue (PB) and its analogues (PBA) with different structures and adjustable compositions have been recognized as promising materials for catalysis, energy storage, and biological applications. Herein, a simple surface anchoring strategy is proposed to achieve the uniform deposition of CeO2 nanocrystals on the double-cone structure surface of PBA (denoted as Ce@Ce–Fe catalyst) for the selective catalytic reduction of NOx with NH3 (NH3-SCR). Compared with Ce–Fe and Ce@CeO2–Fe2O3, the Ce@Ce–Fe catalyst exhibited the best catalytic activity, widest working temperature window, and highest SO2 tolerance, implying its good application in the process of NH3-SCR. Moreover, the catalysts were characterized systematically to elucidate their surface properties and morphological structure. Taking advantage of the excellent redox performance, unique morphology, mesoporous structure with large surface area and pore diameter, and greater acid content, the Ce@Ce–Fe catalyst exhibited a higher NOx performance. In addition, the Ce@Ce–Fe catalyst also exhibited significant resistance to H2O and SO2 due to its higher content of Fe atoms, implying that Fe plays a critical role in this Ce–Fe based catalytic system. More importantly, the present study indicates that well-dispersed active components and unique architectures can effectively enhance the performance of catalysts. [ABSTRACT FROM AUTHOR]

Double perovskites have attracted wide attention due to their low toxicity and good thermal stability. Doping with active elements is a promising method to endow perovskites with excellent optical, electrical or magnetic properties. Herein, a facile aqueous solution method is developed to synthesize Bi3+–Yb3+ co-doped Cs2Na0.6Ag0.4InCl6 double perovskite. Besides the intrinsic warm white self-trapped exciton (STE) emission that originated from the Cs2Na0.6Ag0.4InCl6 host, the samples also exhibit a strong near-infrared emission assigned to the 2F5/2 → 2F7/2 transition of octahedral coordinated Yb3+ ions upon excitation with ultraviolet light. The optimized sample shows a markedly high photoluminescence quantum yield of 84.7%. The photophysical studies such as photoluminescence (PL) and photoluminescence excitation spectra, temperature-dependent PL spectra, and PL decay curves reveal that the strong Yb3+ emission is attributed to the energy transfer from STEs to the Yb3+ ions. Finally, the lead-free double perovskite phosphor-converted LED containing visible and NIR regions was fabricated, with 8.92 mW output power at 100 mA drive current. The results show the great potential of the as-prepared crystals in optoelectronics applications. [ABSTRACT FROM AUTHOR]

MnO2/Fe2O3 nanocomposites were achieved via using KMnO4 and FeCl3 as starting materials in aqueous solution followed by hydrothermal and high-temperature treatment processes. The hydrolysis of FeCl3 produces H+ ions to react with KMnO4 to produce MnO2, which further accelerates the hydrolysis process. The as-synthesized MnO2/Fe2O3 nanocomposites present high oxygen reduction reaction activity with an onset and half-wave potential of 0.953 and 0.859 V vs. RHE, respectively, and a limited current density of 4.875 mA cm−2 at 0.565 V, which are comparable to those of the commercial Pt/C catalyst. The excellent catalytic performance is considered to originate from the high Mn3+ content and the related oxygen vacancies. Furthermore, the unsatisfactory stability of the MnO2/Fe2O3 nanocomposites can be solved by coating with a layer of polyaniline-derived carbon. [ABSTRACT FROM AUTHOR]

A facile fractional crystallization technique was developed to prepare single crystalline CsPb2Br5 films using water as the solvent, and the films can be easily transferred onto various substrates for the device fabrication. The obtained films can be up to 600 × 600 μm2 and decrease to 50 nm in thickness with high crystalline quality as well as temperature and air stability. [ABSTRACT FROM AUTHOR]

A pH-controlled monophasic/biphasic switchable system has been developed as a green and novel strategy for homogeneous catalyst recycling, which has been successfully applied to the Cu-NHC-catalyzed carboxylation of organoboronic esters and benzoxazole with carbon dioxide. Additionally, the present strategy could also be extended to the Ag-NHC-catalyzed carboxylation of terminal alkyne. The tertiary amine-functionalized catalysts could be used for at least four times with a slight loss of activity. [ABSTRACT FROM AUTHOR]

Here we constructed a series of novel non-centrosymmetric structure phosphors [Rb2Zn3(P2O7)2:Mn2+] by a high-temperature solid-state reaction. The multiband emission can be designed by Mn2+ preferentially occupying three types of crystallographic sites in Rb2Zn3(P2O7)2:Mn2+. The emission color could be continuously tuned from yellow-green to orange-red via multiple synergies among crystallographic site engineering, energy transfer, and Mn–Mn dimmers alone through the dopant concentration. These color-tunable phosphors have good thermal stability (I150 °C/I25 °C = 91%). The as-prepared pc-WLED has a low corresponding color temperature (CCT = 4820 K) and a high color rendering index (Ra = 90.4) with CIE color coordinates of (0.351, 0.358). These results show that emission-tunable Rb2Zn3(P2O7)2:xMn2+ phosphors are potential candidates for application in n-UV-based pc-WLED devices. This study offers a new insight for wide-range tuning of PL properties by using crystallographic site engineering through changing the doping level in Mn-activated phosphors. [ABSTRACT FROM AUTHOR]

Gold nanoparticles (AuNPs) with a high specific surface area show efficient activity for the reduction of nitroaromatics. In this study, single-stranded DNA chains (ssDNA, T30, C30 or A30) were used as templates to mediate the formation of AuNPs, and the results demonstrated that the morphologies of the C30-AuNPs or A30-AuNPs had more abundant irregular features than the T30-AuNPs. The catalytic properties and applications of the C30-AuNPs were systematically examined using a reaction model for the reduction of 4-nitrophenol by NaBH4. The effect of different temperatures and pH values on the catalytic activity of C30-AuNPs have been investigated. The C30-AuNPs showed the highest catalytic activity (rate constant kapp = 0.2221 min−1) for the reduction of 4-NP at 35 °C and pH = 7. The conversion of 4-NP to 4-AP using C30-AuNPs followed the Langmuir–Hinshelwood mechanism, which was explained by the principle of promoting electron transfer, i.e. the surface of C30-AuNPs is rich in active sites that promote the process of electron transfer from BH4− to 4-NP, completing the conversion of 4-nitrophenol to 4-aminophenol. Furthermore, the results confirmed that C30-AuNPs were versatile for catalyzing isomers of 4-NP and azo dyes, such as 2-NP, 3-NP, MO, CR and EBT. The results offer new insights into the construction of Au-based catalysts for efficiently removing environmental pollutants. [ABSTRACT FROM AUTHOR]

In this work, a method of preparing boron nanoparticles using copper–boron alloy is presented, and the growth mechanism of boron nanoparticles is analyzed. It was found that sharp eutectic boron in copper–boron alloy can be spheroidized through adjustment of the cooling rate. By comparing three elements Al, Mg and Si, Mg can further control the morphology of eutectic boron and achieve further spheroidization of eutectic boron by limiting the emergence and growth of dendrites. Boron spheres as well as amorphous boron spheres were obtained by extracting the Cu–B alloy which had been spheroidized. The growth mechanism of eutectic boron and boron spheres has been analyzed by HRTEM. Solid boron spheres with curved lattice fringes and obvious crystal defects can be observed. Lattice puckering can be seen in amorphous boron spheres. Moreover, we also report a simple method to prepare hollow boron spheres which consist of multiple crystals and these crystals can form perfect coherent interfaces through twins. Twins and dislocations play an important role in the globular growth of boron. [ABSTRACT FROM AUTHOR]

Mercurous halide crystals, which crystallize in a one-dimensional chain-like structure, have attracted great attention as polarizing and acousto-optic devices in the long wave infrared range for their large birefringence, a wide transparent range, and a large acousto-optic figure of merit. However, it is difficult to obtain large-size single crystals with high quality due to the severe layered cleavage nature of crystals. Additionally, crystal processing still remains a challenge owing to the soft brittleness and cleavage nature. To date, high-quality, large-size mercury halide crystals have been successfully obtained by our group. Herein, micro-striations in the (001) surface of the mercury halide crystals caused by the cleavage along the 〈110〉 orientation in mechanical polishing were reported for the first time. The crystal micro-striations act as diffraction gratings, producing "diffraction spots" when illuminated by light. These cleavage striations seriously deteriorate the crystal crystallinity, enlarging the full width at half maximum (FWHM) of the X-ray rocking curves for the polished surfaces. But the striations on the crystal surface can be effectively attenuated by optimizing the polishing process. The discovery and effective suppression of micro-striations in mercurous halide crystals lay a solid foundation for the fabrication of polarizing and acousto-optic devices with high performance in the long-waved infrared range. [ABSTRACT FROM AUTHOR]

An efficient and generally applicable protocol for the palladacycle-catalyzed arylation of diisopropyl H-phosphonate in water was developed. The remarkable features of this C–P bond-forming reaction include wide substrate scope including the inactive electron-rich and electron-neutral aryl chlorides, the weak inorganic base KF instead of strong bases such as KOtBu or NaOtBu for the activation of C–Cl bond, and the addition of isopropanol to avoid the decomposition of diisopropyl H-phosphonate. [ABSTRACT FROM AUTHOR]

The hydrosilylation of alkenes in a supercritical CO2(scCO2)/ionic liquid (IL) system was investigated. Rh(PPh3)3Cl exhibited excellent catalytic activity and selectivity. KOtBu was used as an additive, and no hydrogenation by-product (alkane) was detected in the scCO2/IL system. During hydrosilylation in the scCO2/IL system, the reactants were possibly transferred into the IL phase by scCO2, in which the catalyst was dissolved. The products can be flushed with scCO2after the reaction and the catalyst/IL system reused. [ABSTRACT FROM AUTHOR]