•A p-n heterojunction of CuI/TiO2 is constructed.•CuI/TiO2 is used as the support for depositing Pt nanoparticles.•Enhanced catalytic activity of MOR by using Pt-CuI/TiO2 under light irradiation.•Improved charger separation contributes to enhanced photoelectrocatalytic activity.In this paper, a p-n heterojunction including p-type CuI and n-type TiO2 is first time constructed to be the support for the deposition of Pt. The as-prepared Pt-CuI/TiO2 modified electrode is studied for the electrocatalytic oxidation of methanol both in dark and under light illumination. Compare to traditional electrocatalytic oxidation, the electrocatalytic activity of Pt-CuI/TiO2 for methanol oxidation is improved with 4.0 times upon light illumination. Moreover, compare to bare CuI and TiO2 upon light illumination, the heterostructure of CuI/TiO2 displays 4.3 and 9.1 times enhanced electrocatalytic activity for methanol oxidation, respectively. The synergistic effects of photocatalysis and electrocatalysis as well as the effective charge transport in the p-n heterojunction of Pt-CuI/TiO2 contribute such big enhancement. The present studies indicate that the constructing of p-n heterojunction provides more insights in the fields of photoelectrochemical and photo–assisted fuel cell system.Download high-res image (86KB)Download full-size image

A strategy for Cd1−xZnxWO4 (x < 0.5) solid solution growth was successfully achieved by the Czochralski method. Polycrystalline samples and crystals of the Cd1−xZnxWO4 system were studied using X-ray diffraction. Furthermore, the scintillation properties of Cd1−xZnxWO4 (x < 0.5) crystals were investigated. It was found that the diffraction peaks of the polycrystalline Cd1−xZnxWO4 (x = 0–1.0) system shift toward higher 2θ angles with increasing degree of Zn substitution. A linear relation between the zinc composition x and the lattice parameters of Cd1−xZnxWO4 crystals existed. With increasing zinc content x, the lattice parameters a, b, and c decrease, and the volume of the unit cell decreases. The shift of the lattice parameter presents a trend from CdWO4 to ZnWO4. Energy dispersive X-ray (EDAX) analysis was carried out in order to confirm the composition of Cd1−xZnxWO4 single crystals (x < 0.5). Optical measurements revealed that the solid solution crystals had a high optical transmittance of about 65% in the range of 350–600 nm, and the absorption edges of Cd1−xZnxWO4 crystals exhibit increasing peaks from 317.4 nm to 321.5 nm. The emission peaks showed a red shift from 465.4 nm to 501.2 nm with the increasing content of zinc. Furthermore, it was observed that the light output (L.O.) decreases and the energy resolution (E.R.) increases with the increase in zinc content.

The new nonlinear optical crystal Rb3V5O14 has been synthesized by solid state reaction and characterized by single-crystal X-ray diffraction, IR and thermogravimetric analysis. The crystal Rb3V5O14 crystallizes in the trigonal system with space P31m (No. 157), a=b=8.7134(12) Å, c=5.2807(11) Å and α=90°, β=90°, γ=120°, Z=1, ρ=3.516 g/cm3. It is a layered structure that is very flat and strongly parallel to c. The V5O14 layer structure consists of corner-linked square and triangular pyramids. The layers are separated by Rb+ ions, which fit equally well on the V5O14 layer. The Kurtz powder SHG measurement, using 1064 nm radiation, showed that the second-harmonic generation efficiency of Rb3V5O14 is about two times that of KDP.The new nonlinear optical crystal Rb3V5O14 has been synthesized by solid state reaction and characterized by single-crystal X-ray diffraction, IR and thermogravimetric analysis. The crystal Rb3V5O14 crystallizes in the trigonal system with space P31m (No. 157), a=b=8.7134(12) Å, c=5.2807(11) Å and α=90°, β=90°, γ=120°, Z=1, ρ=3.516 g/cm3. It is a layered structure that is very flat and strongly parallel to c. The Kurtz powder SHG measurement, using 1064 nm radiation, showed that the second-harmonic generation efficiency of Rb3V5O14 is about two times that of KDP.

Acetonitrile solvent was applied to grow CuI crystals by the cycle-evaporation method with Cu as the reductant. The growth temperature was 70 °C. The process was performed in a nitrogen atmosphere. Clear, millimeter-scaled CuI single crystals were obtained. Moreover, UV−visible spectra, IR spectra, and XRD were used to investigate the redox processes in the solution. The crystal was characterized by X-ray powder diffraction and differential thermal /thermogravimetry analysis.