Latest ArticlesThe photocatalytic conversion of biomass into high-value chemicals, coupled with simultaneous hydrogen (H2) evolution, leveraging the electrons and holes generated by solar energy, holds great promise for addressing energy demands. In this study, we constructed a dual functional photocatalytic system formed by NiS loaded on Ni doped two-dimensional (2D) CdS nanosheet (NiS/Ni-CdSNS) heterostructure for visible-light-driven H2 evolution and ethanol oxidation to acetaldehyde. Remarkably, the 2D NiS/Ni-CdSNS exhibited significant activity and selectivity in both photocatalytic H2 evolution and ethanol oxidation, achieving yields of 7.98 mmol g−1 h−1 for H2 and 7.33 mmol g−1 h−1 for acetaldehyde. The heterogeneous interface of the composite facilitated efficient charge separation, while NiS provided abundant sites for proton reduction, thereby promoting the overall dual-functional photocatalytic activity. Density functional theory calculations further reveal that both Ni doping and NiS loading can reduce the reaction energy barrier of ethanol oxidation of free radicals, and NiS/Ni-CdSNS composite materials exhibit stronger ethanol C-H activation ability to generate key intermediate •CH(OH)CH3 on the surface. This work serves as a valuable guide for the rational design of efficient dual functional photocatalytic systems that combine H2 evolution with the selective conversion of organic compounds into high-value chemicals.
Herein, the degradation of florfenicol (FLO) over zero-valent iron (ZVI) enhanced by SiC was systematically investigated. It was found that 5 g/L of ZVI/SiC (1:3) at pH 3.0 could completely degrade 20 mg/L of FLO within 1 h, with a Kobs value of 0.0873 min−1, 12.5 times greater than that of pure ZVI (0.0069 min−1). Vibrating sample magnetometer (VSM) characterizations revealed that the use of SiC supporter reduces the magnetic intensity of ZVI, which mitigates iron particle agglomeration, increases Brunauer-Emmett-Teller (BET) surface area, and enhances FLO degradation efficiency. Furthermore, ZVI/SiC exhibits a much lower hydrogen evolution potential (HEP) and significantly higher corrosion currents compared to pure ZVI. FLO was proposed to undergo degradation via reductive dechlorination, involving a hydrogenolysis mechanism that entails the cleavage of the σ bond. This study provides new insights into the reduction hydrogenation mechanism of ZVI.
Herein, we report the first visible-light photoredox-catalyzed carboxylation of aryl epoxides with CO2 to synthesize hydroxy acid derivatives. A variety of valuable β-, γ-, δ-, ε-hydroxy acid derivatives are obtained in moderate to high yields under mild conditions. This protocol shows noteworthy functional-group compatibility, high chemo- and regioselectivities under transition-metal-free conditions with an inexpensive organo-dye as photosensitizer. Mechanistic studies indicate that the benzylic carbanion is generated as an intermediate via the sequential single electron transfer (SSET) process.
The stable coordinated metallo-complexes based on 2,2′:6′,2″-terpyridine (tpy) and its derivatives have been widely researched for various wide-ranging applications in photoelectronics, catalysis, sensor, photoluminescence, and so on. However, the most reported studies ignored the comprehensive comparison between structures modified by different positions and photoluminescence. Herein, we design a series of metallo-complexes which were assembled with tpy substituted triphenylamine (TPA) at different positions and metal ions and explored their photophysical properties. In the solution state, MLE2 based on the 5,5″-positions modification showed the highest PLQYs and PL intensity. With the increase of solvent polarity, MLB2 exhibit the largest redshift. In the solid state, from MLA2 to MLE2, the emission colours are gradually red-shifted from yellow to red. The findings in this work may pave a new way to design functional metallo-complexes, not just for PL properties.
The development of large-scale cell cultivation and non-invasive cell harvesting is highly desired in various fields, including biological regeneration and pharmaceutical research. When using traditional microcarriers for cell culture, trypsinization is often necessary during cell collection, leading to partial cells damage. In this work, we developed a thermoresponsive glass microcarrier modified with poly(γ-propargyl-ʟ-glutamate) (PPLG) and poly(N-isopropylacrylamide) (PNIPAM). We utilized these microcarriers for three-dimensional cell culture and enzyme-free cell harvesting, and the results indicated that the prepared microcarriers exhibited excellent non-invasive cell culture performance.
Disgusting deposits (e.g., scale and crude oil) in daily life and industrial production are always serious problems, posing great threats to the safety and economic development. However, most of developed coatings can only conquer one part of these deposits such as superhydrophobic coatings possess anti-scaling capacity but would adhere crude oil. To integrate scale resistance with oil repellence, we herein report a robust superamphiphobic (SAB) coating simultaneously reducing pollution of scale and oil for extended period of time (two weeks with over 98% reduction). Compared with single role of superhydrophobic and amphiphilic surfaces, the SAB coating can not only inhibit interfacial nucleation of scale but also reduce the adhesion of formed scale and polluted oil. The durability of the SAB coating is evaluated via mechanical tests (sandpaper abrasion, tape stripping and sand falling) and chemical corrosion (corrosive liquid immersing), revealed by sustainable high contact angles and low contact angle hysteresis of water and oil. The universality of this strategy can be further confirmed by adding different particles like kaolin, Al2O3, and SiO2, resisting multiple types of scale (i.e., CaSO4, BaSO4 and MgCO3) and oil (i.e., glycerol, glycol, and mineral oil). Therefore, this study provides an ideal avenue for resisting scale and oil, which may be used for conquering the complexity of application environments (e.g., oil production and transportation).
Here, we designed asymmetric (mDS) and symmetrical (dDS) chiral V-shaped molecules by linking one or two dansyl groups to trans-1,2-cyclohexane diamine and investigated the solvent-regulated structural transformation and inversed circularly polarized luminescence (CPL) in the self-assemblies. Upon increasing water volume fraction (fw) in the mixed solvent of water/acetonitrile, asymmetric mDS selfassembled into hollow nanospheres and microtubes, while solid nanospheres and solid microplates were corresponding to symmetric dDS. During this transformation process, the emission of mDS and dDS was changed from yellow-green to blue and cyan color, which was ascribed to twisted intramolecular charge transfer (TICT) and locally excited (LE) fluorescence of V-shaped DS molecules. The conformation of N,N-dimethyl groups with respect to naphthalene ring also led to the transformation of structures. These tubular and platelike structures had stronger and reversed CPL signals in comparison with spheroidal structures. The chiral information of DS assembly could be effective transferred to achiral Nile red via co-assembly strategy, which endowed Nile red exhibiting inversed induced CPL signal regulated by water fraction. This work provides a method for achieving a variety of self-assembled structures with adjustable chiroptical properties.
Transition-metal-catalyzed cross-electrophile coupling has emerged as a reliable method for constructing carbon–carbon bonds. Herein, we report a general method, cobalt-catalyzed reductive alkynylation, to construct C(sp)-C(sp3) and C(sp)-C(sp2) bonds. This presented reaction has a broad substrate scope, enabling the efficient cross-electrophile coupling between alkynyl bromides with alkyl halides and aryl or alkenyl (pseudo)halides. This presented reaction is conducted under mild conditions, tolerating many functional groups, thus suitable for the modification and synthesis of biologically active molecules.
The kinetic of low-temperature carrier and lattice of lead-halide perovskite is yet to be fully understood. In this work, we investigate the steady-state photoluminescences (PLs) of CsPbI3 at the environmental temperature (Te) ranging from 20 K to 300 K, and observed anomalous behaviors at cryogenic temperatures: The carrier temperature (Tc) of pure CsPbI3 exhibits a negative correlation with Te, accompanied by an expansion in Urbach tails of absorption spectra (Abs.) and excessive red-shifts at peak energy of PLs. These phenomena are also observed in those samples containing a certain amount of Cs4PbI6, but to a lesser extent and occurs at lower temperatures. It is attributed to the intensified hot phonon bottleneck effect (HPB) in CsPbI3 at cryogenic Te, which hinders the energy transfer from hot carriers, via longitudinal optics (LO) phonons to longitudinal acoustic (LA) phonons, to the ambient. For samples under continuous-wave laser excitation, in specific, the barrier induced by the enhanced HPB at low Te prevents the effective thermalization among carriers, LO and LA phonons, which, therefore, form thermally isolated ensembles with different temperatures. At cryogenic Te range, the elevated temperatures of carrier and LO phonon expand the high-energy side of PLs and the low-energy tail of Abs., respectively. For those samples in which the CsPbI3 is mixed with Cs4PbI6, the interfacial LO-LO interaction across them provides a bypass for heat dissipation, mitigating the heat accumulation in LO-phonons of CsPbI3. The results suggest that a strong HPB effect may break the thermal equilibrium among different branches of phonons in the lattice under certain extreme conditions.
Cobalt-based phosphides show excellent hydrogen evolution reaction (HER) performance, however, improving the intrinsic activity and stability of it in alkaline electrolyte still remains a challenge. Herein, CoRuOH/Co2P/CF with heterojunction structure was developed by means of molten salt and rapid hydrolysis (30 s). The OH− from rapid surface hydrolysis of Co2P as a hydrogen adsorption site can facilitate the formation of thin CoRuOH layer as a water dissociation site, which may bring out better synergistic effect for alkaline HER. Moreover, the covering of CoRuOH can improve the stability of Co2P for HER. When drives at 100 mA/cm2, it only requires overpotential of 81 mV in 1.0 mol/L KOH (25 ℃). Even at higher current density (1000 mA/cm2), CoRuOH/Co2P/CF can also operate stability for at least 100 h. When coupling with NiFe-LDH/IF in a two-electrode system, the voltage of NiFe-LDH/IF(+) || CoRuOH/Co2P/CF(−) at 1000 mA/cm2 is merely 1.77 V with 100 h, demonstrating great potential for water splitting. The implementation of this work provides a new strategy and reference for the further improvement of transition metal phosphides as HER electrocatalysts.