Kelleyfraser0766

Bimetallic alloy nanospheres hybridized with semiconductor square-shaped discs are promising catalysts for photocatalytic water splitting, because they exhibit multicomponent interactions, high catalytic activity, and stability. Herein, Cu-Pd/N-Bi2WO6 heterostructures consisting of bimetallic Cu-Pd alloy nanospheres uniformly dispersed on N-Bi2WO6 square-shaped discs are reported. The as-prepared 1 wt% Cu-Pd/N-Bi2WO6 catalyst exhibits a higher H2 production rate (4213 µmol/g) under simulated solar light illumination than N-Bi2WO6 (291 µmol/g). The considerably high H2 production rate is ascribed to the exposed catalytically active sites of the Cu-Pd alloy nanospheres, which facilitate the formation of rapid charge transfer channels between Cu-Pd and N-Bi2WO6. Moreover, the photocatalyst stability is improved by aggregation of the highly dispersed Cu-Pd alloy nanospheres on the N-Bi2WO6 surface. Accordingly, a reaction mechanism based on the work functions of the bimetallic Cu-Pd alloy nanospheres and N-Bi2WO6 square-shaped discs is proposed to elucidate the photocatalytic reaction pathway. The holes (which accumulate in the N-Bi2WO6 square-shaped discs) and Pd (which acts as an electron channel) can effectively inhibit the recombination of charge carriers, and Cu (which acts as the cocatalyst) can synergistically increase the H+ reduction rate. This study provides a new effective route for the design of high-performance heterostructures for efficient photocatalytic H2 production.

Contact angle measurements alongside Young's equation have been frequently used to quantitatively characterize the wettabilities of solid surfaces. In the literature, the Wenzel and Cassie-Baxter models have been proposed to account for surface roughness and chemical heterogeneity, while precursor film models have been developed to account for stress singularity. However, the majority of these models were derived based on theoretical analysis or indirect experimental measurements. We hypothesize that sub-nanometer-scale in situ investigations will elucidate additional complexities that impact wettability characterization.

To develop further insights into in situ wettability, we provide the first direct experimental observation of fluid-solid occupancies at three-phase contacts at sub-nanometer resolution, using environmental transmission electron microscopy.

Considering the partially spreading phenomenon and capillarity, we provide an improved physics-based interpretation of measuring the sub-nanometer-Wenzel model is discussed based on the observed in situ solid-fluid occupancies.In this work, we fabricated vanadium/zinc metal-organic frameworks (V/Zn-MOFs) derived from self-assembled metal organic frameworks, to further disperse ultrasmall Zn2VO4 nanoparticles and encapsulate them in a nitrogen-doped nanocarbon network (ZVO/NC) under in situ pyrolysis. When employed as an anode for lithium-ion batteries, ZVO/NC delivers a high reversible capacity (807 mAh g-1 at 0.5 A g-1) and excellent rate performance (372 mAh g-1 at 8.0 A g-1). Meanwhile, when used in sodium-ion batteries, it exhibits long-term cycling stability (7000 cycles with 145 mAh g-1 at 2.0 A g-1). Additionally, when employed in potassium-ion batteries, it also shows outstanding electrochemical performance with reversible capacities of 264 mAh g-1 at 0.1 A g-1 and 140 mAh g-1 at 0.5 A g-1 for 1000 cycles. The mechanism by which the pseudocapacitive behaviour of ZVO/NC enhances battery performance under a suitable electrolyte was probed, which offers useful enlightenment for the potential development of anodes of alkali-ion batteries. The performance of Zn2VO4 as an anode for SIBs/PIBs was investigated for the first time. This work provides a new horizon in the design ZVO/NC as a promising anode material owing to the intrinsically synergic effects of mixed metal species and the multiple valence states of V.Developing high efficient Palladium-metal-based electrocatalysts is of great significance for formic acid oxidation (FAO) reaction. Here, we experimentally synthesize PdAu alloy composited with MnOx electrocatalyst (PdAu-MnOx/C) and illustrate its remarkable FAO performance. By virtue of theory studies, we find that Pd-Au bridges have superior adsorption ability towards HCOO* and oxygen vacancies in MnOx make HCOO* formation from HCOOH easier, synergistically lead to the outstanding FAO performance with specific activity and mass activity of 19.0 mA cm-2 and 4539 mA mg-1Pd+Au respectively, which are 2.6 times and 3.5 times higher than commercial Pd/C. This work shed some light toward development of high-performance Pd-based electrocatalysts for FAO.Conversion of carbon dioxide into useful chemicals has attracted great attention. However, the significant bottlenecks facing in the field are the poor conversion efficiency of CO2 and low selectivity of products. CCR antagonist Herein, hierarchical BiOBr hollow microspheres are fabricated by a solvothermal method using ethylene glycol (EG) as solvent in presence of polyvinyl pyrrolidone (PVP). The hollow BiOBr microspheres prepared at 120 °C exhibit the best performance for CO2 photoreduction. The evolution rates of product CO and CH4 are up to 88.1 µmol g-1h-1 and 5.8 µmol g-1h-1, which are 8.8 times and 5.8 times higher than that of plate-like BiOBr respectively. The hollow microspheres possess larger specific area and generate multiple reflections of light in the cavity, thus enhancing the utilization efficiency of light. The modulated electronic structure by oxygen vacancy (OVs) is beneficial to the transfer of photogenerated electrons and holes. Especially, the enriched charge density of BiOBr by OVs is conductive to the adsorption and activation of CO2, which could lower the overall activation energy barrier of CO2 photoreduction. In summary, the synergistic effect of the hollow structure with OVs plays a vital role in boosting the photoreduction of CO2 for BiOBr. This work provides a new opportunity for designing the high efficiency catalyst by morphology engineering with defects at the atomic level for CO2 photoreduction.Surface engineering of quantum dots (QDs) plays critical roles in tailoring carriers' dynamics of I-III-VI QDs via the interplay of QDs in aggregates or assembly, thus influencing their photocatalytic activities. In this work, an aqueous synthesis and the followed pH tuned oriented assembly method are developed to prepare network-like aggregates, dispersion, or sheet-like assembly of GSH-capped Silver Indium Sulfide (AIS). FTIR, DLS, and HRTEM investigation revealed that surface protonation or deprotonation of QDs occurred at pH 12 favors the formation of network-like aggregates with various defects or sheet-like assembly with perfect crystal lattice, respectively, via the surface charge induced interaction among AIS QDs. Further UV-vis, steady and transient PL investigation confirm the narrowed band gaps and the prolonged PL lifetime of the acidic network-like aggregates. As a result, the optimized network-like aggregates (3.0-AIS) exhibits superior photocatalytic H2 evolution (PHE) rates (5.2 mmol·g-1·h-1), about 113 times that of alkaline sheet-like assembly (13.