Synthesis, Characterization and Electrochemical Behavior of p-NiO/n-TiO_2/Polyaniline Composites

The p-NiO/n-TiO2/polyaniline composites were synthesized via in situ polymerization of aniline. The structure and morphology of the composites were characterized by means of X-ray diffraction（XRD）, scanning electron microscopy（SEM）, Fourier transform infrared spectroscopy（FTIR） and UV-Vis absorption spectroscopy. It was found that the p-n junction p-NiO/n-TiO2 particles were trapped in the polyaniline molecular matrix and the polyaniline was deposited on the surface of the particles to form a kind of flower cluster morphologies. The electrochemical behavior of the polyaniline composites was investigated. The electrochemical reactivity of the polyaniline was influenced by the p-NiO/n-TiO2 particles due to the effect of electron-hole pairs in these p-n junction particles. The reversibility of redox process and current intensity of the polyaniline composites with the changing of potential scan rate were also discussed.

Simultaneous observation of positive and negative giant magnetoresistances in composite （La0.83Sr0.17MnO3） 1-x （ITO）x

We have studied the transport property of the composites （La0.83Sr0.17 MnO3）1-x（ITO）x [ITO=（In2O3）0.95 （SNO2）0.05], which were fabricated by mechanically mixing La0.83Sr0.17MnO3 and ITO grains. A giant positive magnetoresistance （PMR） has been observed above the Curie temperature Tc for samples with x around 0.40, in addition to the negative magnetoresistanee related to spin-dependent interracial tunnelling below To. For （La0.83Sr0.17MnO3）0.6（ITO）0.4, the magnetoresistive ratio for the PMR can reach 39.3% under a magnetic field H=2.24×10^5A/m. Theoretical analysis suggests that the magnetic-field-induced broadening of the p-n barrier between both kinds of grains and the density of the p-n heterostructures should be responsible for the PMR behaviour.

Two-dimensional Ti_(3)C_(2)T_(X)-nanosheets/Cu_(2)O composite as a high-performance photocatalyst for decomposition of tetracycline

Construction of photocatalysts with a Schottky heterojunction could realize highly efficient and stable degradation of organic pollutes in the wastewater.In this work,a precipitation method was used to prepare Ti_(3)C_(2)T_(X)-nanosheets/Cu_(2)O composite photocatalysts with the Schottky heterojunction for the decomposition of tetracycline(TC)antibiotics under visible light.As-prepared photocatalysts were characterized by various techniques such as X-ray diffraction analysis(XRD),High resolution transmission electron microscopy(TEM)and X-ray photoelectron spectroscopy(XPS).When the best Ti_(3)C_(2)T_(X)-nanosheets/Cu_(2)O composite was applied for the degradation of TC under visible light,the degradation efficiency reached up to 97.6%only in 50 min.It is considered that superoxide radical(O_(2)^(→))and hole(h^(+))were the main reactive species for the TC degradation,and in the Schottky heterojunction,e^(-)-h^(+)pairs in the catalyst could be transferred and separated effectively,resulting in obviously enhanced photocatalytic efficiency and stability.

Facilely anchoring Cu_(2)O nanoparticles on mesoporous TiO_(2)nanorods for enhanced photocatalytic CO_(2)reduction through efficient charge transfer

Semiconductor-employed photocatalytic CO_(2) reduction has been regarded as a promising approach for environmental-friendly conversion of CO_(2) into solar fuels.Herein,TiO_(2)/Cu_(2)O composite nanorods have been successfully fabricated by a facile chemical reduction method and applied for photocatalytic CO_(2) reduction.The composition and structure characterization indicates that the Cu_(2)O nanoparticles are coupled with TiO_(2) nanorods with an intimate contact.Under light illumination,all the TiO_(2)/Cu_(2)O composite nanorods enhance the photocatalytic CO_(2)reduction.In particular,the TiO_(2)/Cu_(2)O-15%sample exhibits the highest CH_(4)yield(1.35μmol g^(-1)h^(-1)) within 4 h irradiation,and it is 3.07 and 15 times higher than that of pristine TiO_(2)nanorods and Cu_(2)O nanoparticles,respectively.The enhanced photoreduction capability of the TiO_(2)/Cu_(2)O-15%is attributed to the intimate construction of Cu_(2)O nanoparticles on TiO_(2) nanorods with formed p-n junction to accelerate the separation of photogenerated electron-hole pairs.This work provides a reference for rational design of a p-n heterojunction photocatalyst for CO_(2) photoreduction.