Quantum dots (QDs), ac lass of promising candidates for harvesting visible light, generally exhibit low activity and selectivity towards photocatalytic CO 2 reduction. Functionalizing QDs with metal complexes (or metal cations through ligands) is aw idely used strategy for improving their catalytic activity;h owever,t he resulting systems still suffer from lowselectivity and stability in CO 2 reduction. Herein, we report that doping CdS QDs with transition-metal sites can overcome these limitations and provideasystem that enables highly selective photocatalytic reactions of CO 2 with H 2 O (100 %s electivity to CO and CH 4 ), with excellent durability over 60 h. Doping Ni sites into the CdS lattice leads to effective trapping of photoexcited electrons at surface catalytic sites and substantial suppression of H 2 evolution. The method reported here can be extended to various transition-metal sites,a nd offers new opportunities for exploring QD-based earth-abundant photocatalysts.

Uniform ultrathin Pt nanotubes, Pt and Pd nanowires with diameters of only several nanometers and a very‐high aspect ratio of ∼10 000 can be fabricated using ultrathin Te nanowires as both reducing agent and sacrificial template in ethylene glycol. The valences of metal precursors have a crucial effect on the morphology of the nanostructures.

New covalently tethered CO2 adsorbents are synthesized through the in situ polymerization of N-carboxyanhydride (NCA) of l-alanine from amine-functionalized three-dimensional (3D) interconnected macroporous silica (MPS). The interconnected macropores provide low-resistant pathways for the diffusion of CO2 molecules, while the abundant mesopores ensure the high pore volume. The adsorbents exhibit high molecular weight (of up to 13058 Da), high amine loading (more than 10.98 mmol N g(-1)), fast CO2 capture kinetics (t1/2 < 1 min), high adsorption capacity (of up to 3.86 mmol CO2 g(-1) in simulated flue gas and 2.65 mmol CO2 g(-1) in simulated ambient air under 1 atm of dry CO2), as well as good stability over 120 adsorption-desorption cycles, which allows the overall CO2 capture process to be promising and sustainable.

A modified quick, easy, cheap, effective, rugged and safe (QuEChERS) method with multi-walled carbon nanotubes (MWCNTs) as a reversed-dispersive solid-phase extraction (r-DSPE) material combined with gas chromatography-mass spectrometry was developed for the determination of 14 pesticides in complex matrices. Four vegetables (leek, onion, ginger and garlic) were selected as the complex matrices for validating this new method. This technique involved the acetonitrile-based sample preparation and MWCNTs were used as the r-DSPE material in the cleanup step. Two important parameters influencing the MWCNTs efficiency, the external diameters and the amount of MWCNTs used, were investigated. Under the optimized conditions, recoveries of 78-110% were obtained for the target analytes in the complex matrices at two concentration levels of 0.02 and 0.2 mg/kg. In addition, the RSD values ranged from 1 to 13%. LOQs and LODs for 14 pesticides ranged from 2 to 20 μg/kg and from 1 to 6 μg/kg, respectively.

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Knowledge of human exposure to imidacloprid, the most extensively used insecticide, and para-hydroxybenzoic acid esters (parabens), the most extensively used preservative, is insufficient. In this study, 295 urine samples collected from subjects in rural and urban areas in China were analyzed for imidacloprid and four parabens (namely, methyl paraben, ethyl paraben, propyl paraben, and butyl paraben) as well as their major metabolites (namely, 6-chloronicotinic acid (6-ClNA) and para-hydroxybenzoic acid (p-HB)). Imidacloprid was detected in 100% of the urine samples from rural Chinese subjects and 95% of the urine samples from urban Chinese subjects. Concentrations of urinary imidacloprid detected in rural Chinese subjects (geometric mean (GM) = 0.18 ng/mL) were slightly higher than those detected in urban Chinese subjects (GM = 0.15 ng/mL) when the effect of pesticide spraying was excluded. However, concentrations of urinary imidacloprid detected in rural adults increased significantly in the subsequent days of pesticide spraying (GM = 0.62 ng/mL), which could return to the normal levels within 3 days. In contrast, concentrations of urinary parabens detected in rural Chinese subjects (GM = 6.90 ng/mL) were lower than that in urban Chinese subjects (GM = 30.5 ng/mL). In addition, the metabolism characteristics of imidacloprid to 6-ClNA and parabens to p-HB were discussed preliminarily.