Assisting Bi_(2)MoO_(6) microspheres with phenolic resin-based ACSs as attractive tailor-made supporter for highly-efficient photocatalytic CO_(2) reduction

It is rather essential to design glorious system with high CO_(2) adsorption capacity and electron migration efficiency for improving selective and effective CO_(2) reduction into solar fuels.Here,as-synthesized phenolic resin spheres via suspension polymerization were carbonized and activated by water vapor to obtain activated carbon spheres(ACSs).Subsequently,Bi_(2)MoO_(6)/ACSs were prepared via hydrothermal-impregnated method.The systematical characterizations of samples,including XRD,XPS,SEM,EDX,DRS,BET,PL,CO_(2) adsorption isotherm,EIS and transient photocurrent,were analyzed.The results clearly demonstrated that Bi_(2)MoO_(6) with suitable oxidation reduction potentials and bandgap and ACSs with admirable CO_(2) adsorption and electrical conductivity not only enhanced separation efficiency of photoindued electron-hole pair,but also displayed as 1.8 times CO_(2) reduction activity to CO as single Bi_(2)MoO_(6) sample under Xe-lamp irradiation.Finally,a concerned photocatalytic CO_(2) reduction mechanism was proposed and investigated.Our findings should provide innovative guidance for designing a series of photocatalytic CO_(2) reduction materials with highly efficient and selective ability.

Adsorption equilibrium, kinetics, and dynamic separation of Ca2+ and Mg2+ ions from phosphoric acid–nitric acid aqueous solution by strong acid cation resin

The separation of Ca2+and Mg2+ions from phosphoric acid-nitric acid aqueous solution is very significant for the neutralization process of nitrophosphate fertilizer.This paper studied the adsorption equilibrium,kinetics,and dynamic separation of Ca2+and Mg2+ions by strong acid cation resin,and the effects of phosphoric acid and nitric acid on the adsorption process were investigated.The results reveal that the adsorption process of Ca2+and Mg2+ions in pure water on resin is in good agreement with the Langmuir isotherm model and their maximal adsorption capacities are 1.86 mmol·g-1 and 1.83 mmol·g-1,respectively.The adsorption kinetics of Ca2+and Mg2+ions on resin fits better with the pseudo-first-order model,and the adsorption equilibrium in pure water is reached within 10 min contact time,while at the present of phosphoric acid,the adsorption rate of Ca2+and Mg2+ions on resin will go down.The dynamic separation experiments demonstrate that the designed column adsorption is able to undertake the separation of metal ions from the mix acids aqueous solution,but the dynamic operation should control the flow rate of mix acid solution.Besides nitric acid solution was proved to be effective to completely regenerate the spent resin and achieve the recyclable operation of separation process.

Citric acid-assisted synthesis of nano-Ag/BiO Br with enhanced photocatalytic activity

In this study, silver nano-particles have been anchored in the surface of Bi OBr photocatalysts by a citric acid-assisted photoreduction method. The citric acid was served as a chelating and reductive agent for the preparation of Ag-decorated Bi OBr photocatalysts(named as Ag/Bi OBr-2). The as-synthesized samples were characterized by X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), scanning electron microscopy(SEM), transmission electron microscopy(TEM), and UV-Vis diffuse reflection spectroscopy(DRS). The Ag/Bi OBr-2 photocatalyst exhibited excellent and stable photocatalytic activities on MO and phenol degradation under simulated sunlight irradiation. The enhanced photocatalytic activity could be ascribed to the smaller size, rough surface, and the surface plasma resonance(SPR) effect of Ag. Also, the Schottky junction, between the surface of the Bi OBr and silver nanoparticles, accelerated the efficient transfer and separation of photoinduced electron-hole pairs and promoted the photocatalytic performance. The active species tests indicated that the superoxide radical(·O-2) was responsible for the enhanced photocatalytic performance of Ag/Bi OBr-2. Finally, a possible photocatalytic mechanism was proposed.

Adsorption Mechanism of Acetylene Hydrogenation on the Pd (111) Surface

First-principles calculations are carried out to examine the adsorption of acetylene over the Pd(111)surface.A hydrogen adsorption system is initially investigated to confirm the reliability of the selected calculation method.Adsorption energies,Mulliken-populations,overlap populations,charge density,and projected density of states(PDOS)are then calculated in the optimised acetylene adsorption system.Results show that C_(2)H_(2) molecule tends to adsorb through the threefold parallel-bridge configuration that is computed to be the most stable.In this structure,the distance of the C-H bond is calculated to be 1.09 Å,and the C-C-H bond angle is 128°.The distance of the C-C bond in acetylene is 1.36 Å,increasing from 1.21 Å in the gas phase.Moreover,the C-C bond overlap population decreases from 1.98 to 1.38,revealing that the carbon configuration in C2H2 rehybridises from sp to sp^(2) and beyond.The obtained results are compared with available experimental studies on acetylene hydrogenation on single-metal surfaces.The PDOS study indicates that a carbonaceous layer may generate on the metal surface during acetylene adsorption.The carbonaceous layer can affect the adsorption and reaction of acetylene,thereby inactivating the metal surface.Our experiments also show that Pd exhibits high catalytic activity.