Controlled Growth of NiMoO_(4) Nano-rods on Carbon Cloth:A Novel Electrode for the Hydrogen Evolution Reaction in Alkaline Media and Simulated Sea Water

A series of NiMoO_(4)-nano rod/carbon cloth composite electrodes with different loadings(x)of NiMoO_(4)-NRs was synthesized with a view to implementing an efficient hydrogen evolution reaction(HER).The NiMoO_(4) nano-rods(NRs)were prepared by growing them directly on carbon cloth(CC)via a simple hydrothermal reaction coupled with an annealing treatment.The resulting NiMoO_(4)-NR/CC-x composites served directly as electrodes for electrolysis of an alkaline medium and a simulated sea water.The results indicated that among the NiMoO_(4)-NR/CC-x composites,the NiMoO_(4)-NR/CC-10 composite possessed the highest HER activity with an overpotential of 244.8 mV at 10 mA/cm^(2),a Tafel slope of 95 mV/dec,the fastest charge transfer rate(R_(ct)<1Ω)and good stability in alkaline media.Even in simulated seawater,the NiMoO_(4)-NR/CC-10 composite showed good stability.The outstanding HER activity and stability may originate from the strong interaction between Ni and Mo in the NiMoO_(4) NRs as well as the efficient charge transfer process and the rate of the HER due to the synergistic effect involving the CC and NiMoO_(4) NRs.

Semiconductor ZnO Nano-Rods Thin Film Grown on Silver Wire for Hemoglobin Biosensor Fabrication

Wurtzite hexagonal ZnO semiconductor nano-rods (NRs) thin films were grown on silicon substrates and silver wire with diameter equal 68 nm. Sol gel (SG) and aqueous chemical growth (ACG) methods by two steps of preparation (seed layers and nano-rod growth) are used for samples preparation. The structural and morphological properties are evaluated using X-ray diffraction (XRD) and scanning electron microscope (SEM). The proposed iron ion sensor has shown good linearity for a wide concentration range from 0.078 M/L to 0.26 M/L of iron ions. The results show that the electrode is highly sensitive to iron ions with a slope around 47.8 mV/decade with a regression coefficient R2 = 0.96.

Investigation of the Impact of Calcinations Temperature on the Prop-erties of Ba Doped HfO2 Nano-rods

Barium doped hafnium oxide nanoparticles were synthesized by an easy co-precipitation method. FTIR analysis and EDX investigation shows the purity and stoichiometric composition of hafnium oxide nanoparticles. XRD investigation exhibit the as syn-thesized nanoparticles are amorphous in nature and calcined barium doped hafnium oxide nanoparticles have the monoclinic phase structure with the mean crystallite size was around 15 nm. TEM analysis shows the development of crystalline Nano-rods. The Na-no-rod formations signify the possibility of its use in applications of sensor. Ultra violet visible spectroscopy investigation shows that the band gap of the nanoparticles is noticed between 5.4-5.14 eV. The visible and NIR of barium doped hafiniura oxide nanoparticles indicated high reflectance, which may possibly be employ as an antireflection coating in solar cells applications and high absorbance ultra violet region signify the viability of make use of the prepared nanoparticles could be used in Opto-electronic device applica-tions.

Cu clusters immobilized on Cd-defective cadmium sulfide nano-rods towards photocatalytic CO_(2)reduction

Single-site metal atoms or clusters(SMCs)present high potential to enable the exploration of energetics and kinetics in heterogeneous photocatalysis owing to their unique properties.Here,we report the first work for highly no ligands-protected atomic-level Cu clusters by mediating them in Cd vacancies at the edge of Cd S nanorods(Cu CR SCC)towards photocatalytic CO_(2)conversion.X-ray absorption spectrometric analysis and photoelectric dynamic characterizations demonstrate that the well-defined Cu clusters across the Cd vacancies induce a synergistic effect on CO_(2)reduction through the interfacial conjunction,accelerating charge carrier mobility and facilitating atom utilization.In situ diffuse reflectance infrared Fourier transform spectroscopy,low-coverage calculated isosteric heat,and theoretical studies unveil that the direct cluster/substrate conjunction provides a driving force for interfacial electronic modification and dynamic cooperation.Besides,Cu acts as the active site in the process of CO_(2)photoreduction,which enhances the adsorption and activation of CO_(2).Consequently,this leads to outstanding CO_(2)-to-CO conversion with a turnover number of more than 90 without the addition of any sacrificial agent.Particularly,the Cu clusters-mediated Cd S nanorods are able to serve as carrier provider,allowing the photogenerated electrons transfer from Cd S to Cu clusters.These electrons received from Cd S can further enhance the charge carrier separation and thus achieve high photostability during longtime light irradiation.

Acetone Sensors Based on La^(3+) Doped ZnO Nano-rods Prepared by Solvothermal Method

La3＋ doped ZnO nano-rods with different doping concentration were prepared via solvothermal method.The doped ZnO nano-rods were characterized by X-ray diffraction（XRD） and scanning electron microscopy（SEM）,respectively.The effect of La3＋ doping on the gas-sensing properties was investigated.The results revealed that the sensor based on 6 mol% La3＋ doped ZnO nano-rods exhibited high response to dilute acetone,and the responses to 0.01×10-6 acetone reached 2.4 when operating at 425 ℃.The response time and the recovery time for 0.01×10-6 acetone were only 16 and 3 s,respectively.

SnO_2 nano-sheet as an efficient catalyst for CO oxidation

Polycrystalline SnO2 fine powder consisting of nano-particles （SnO2-NP）, SnO2 nano-sheets （SnO2-NS）, and SnO2 containing both nano-rods and nano-particles （SnO2-NR＋NP） were prepared and used for CO oxidation. SnO2-NS possesses a mesoporous structure and has a higher surface area, larger pore volume, and more active species than SnO2-NP, and shows improved activity. In contrast, although SnO2-NR＋NP has only a slightly higher surface area and pore volume, and slightly more active surface oxygen species than SnO2-NP, it has more exposed active （110） facets, which is the reason for its improved oxidation activity. Water vapor has only a reversible and weak influence on SnO2-NS, therefore it is a potential catalyst for emission control processes.

Pyroelectric Bi_5-x(Bi₂S₃)₃₉I₁₂S: Fibonacci Superstructure, Synthesis Options and Solar Cell Potential

Previously, synthetic hexagonal bismuth sulfide iodide (polar space group P63, a = 15.629(3) ?, c = 4.018(1) ?, Z = 2) has been described by the rather unsatisfactory fractional formula Bi19/3IS9 [1] 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F005200650066003400310037003600350038003400370039000000 -[3] 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F005200650066003400310037003600350038003400370036000000 . A redetermination of the structure using old but reliable photographic intensity data indicated the presence of additional split positions and reduced atomic occupancies. From the observed pattern of this “averaged” structure a consistent model of a superstructure with lattice parameters of a' = √13·a = 56.35(1) ?, c' = c, and a formula Bi5-x(Bi2S3)39I12S emerged, with 2 formula units in a cell of likewise P63 space group. Structural modulation may be provoked by the space the lone electron pair of Bi requires. When Bi on the 0, 0, z position of the “averaged” cell is transferred to two general six-fold sites and one unoccupied twofold one of the super-cell, more structural stability is guaranteed due to compensation of its basal plane dipole momentum. Owing to the limited intensity data available, more details of the superstructure are not accessible yet. Some physical properties and solar cell application are discussed together with suggestions of ambient temperature synthesis routes of c-axis oriented nano-rod sheets.