Insight into the synergistic effect of defect and strong interface coupling on ZnIn_(2)S_(4)/CoIn_(2)S_(4)heterostructure for boosting photocatalytic H_(2) evolution

Steering the directional carrier migration across the interface is a central mission for efficient photocatalytic reactions.In this work,an atomic-shared heterointerface is constructed between the defect-rich ZnIn_(2)S_(4)(HVs-ZIS)and CoIn_(2)S_(4)(CIS)via a defect-guided heteroepitaxial growth strategy.The strong interface coupling induces adequate carriers exchanging passageway between HVs-ZIS and CIS,enhancing the internal electric field(IEF)in the ZnIn_(2)S_(4)/CoIn_(2)S_(4)(HVs-ZIS/CIS)heterostructure.The defect structure in HVs-ZIS induces an additional defect level,improving the separation efficiency of photocarriers.Moreover,promoted by the IEF and intimate heterointerface,photogenerated electrons trapped by the defect level can migrate to the valence band of CIS,contributing to massive photogenerated electrons with intense reducibility in HVs-ZIS/CIS.Consequently,the HVs-ZIS/CIS heterostructure performs a boosted H_(2)evolution activity of 33.65 mmol g^(-1)h^(-1).This work highlights the synergistic effects of defect and strong interface coupling in regulating carrier transfer and paves a brave avenue for constructing efficient heterostructure photocatalysts.

Distribution of nitric oxide synthase positive neurons in the substantia nigra of rats with liver cirrhosis

BACKGROUND：Nitrogen monoxide plays an important role in the physiological activity and pathological process of striatum in substantia nigra, and the nitric oxide synthase in substantia nigra may have characteristic changes after liver cirrhosis.OBJECTIYE： To observe the distribution and forms of nitric oxide synthase （NOS） positive neurons and fibers in substantia nigra of rats with liver cirrhosis.DESIGN： A comparative observational experiment.SETTINGS： Beijing Friendship Hospital; Capital Medical University.MATERIALS： Twenty 4-month-old male Wistar rats （120 - 150 g） of clean grade, were maintained in a 12-hour light/dark cycle at a constant temperature with free access to standard diet and water. Cryostat microtome （LEICA, Germany）; All the reagents were purchased from Sigma Company.METHODS： The experiment was carried out in the Department of Anatomy （key laboratory of Beijing city）,Capital Medical University from July 2000 to March 2002. The rats were randomly divided into normal group （n=10） and liver fibrosis group （n=10）. Rats in the liver fibrosis group were subcutaneously injected with 60% CCl4 oil at a dose of 5 mL/kg for the first time, and 3 mL/kg for the next 14 times, twice a week,totally 15 times. Liver fibrosis of grades 5 - 6 was taken as successful models. Whereas rats in the normal group were not given any treatment. Four months after CCl4 treatment, all the rats were anesthetized to remove brain, and frontal frozen serial sections were prepared. The expressions of nitric oxide synthase positive neurons in substantia nigra of rats were observed under inverted microscope. The number and gray scale of cell body of nitric oxide synthase positive neurons in substantia nigra were detected with NADPH-diaphorase staining.MAIN OUTCOME MEASURES： ①Number and gray scale of cell body of nitric oxide synthase positive neurons in substantia nigra; ②Expressions of nitric oxide synthase positive neurons in substantia nigra.RESULTS： All the 20 rats were involved in the analysis of results. ①The nitric oxide synthase positive neurons in substantia nigra were obviously fewer in the liver cirrhosis group than in the normal group （P〈0.01）, and the gray scale of the positive cell body was higher in the liver cirrhosis group than in the normal group （P〈0.05）. ② Abundant nitric oxide synthase positive neurons were observed in substantia nigra of neurons in substantia nigra were obviously fewer in the liver cirrhosis group than in the normal group （P〈0.01）, and the gray scale of the positive cell body was higher in the liver cirrhosis group than in the normal normal rats, the cell body of nitric oxide synthase positive neurons was clear and transparent, with short own cloudy processes. In substantia nigra of rats with liver cirrhosis, the body of nitric oxide synthase positive neurons were observed shrink obviously, less fibrin than normal.CONCLUSION： Rats with liver cirrhosis may suffer from the physiological dysfunction of neurons due to lack of fibers. The nitric oxide synthase positive neurons in substantia nigra can shrink and reduce.

Surface reconstruction,doping and vacancy engineering to improve the overall water splitting of CoP nanoarrays

Development of a general regulatory strategy for efficient overall water splitting remains a challenging task.Herein,a simple,costfairness,and general fluorination strategy is developed to realize surface reconstruction,heteroatom doping,and vacancies engineering over cobalt phosphide(CoP)for acquiring high-performance bifunctional electrocatalysts.Specifically,the surface of CoP nanoarrays(NAs)becomes rougher,meanwhile F doped into CoP lattice and creating amounts of P vacancies by fluorination,which caused the increase of active sites and regulation of charge distribution,resulting the excellent electrocatalyst performance of F-CoP NAs/copper foam(CF).The optimized F-CoP NAs/CF delivers a lower overpotential of only 35 mV at 10 mA·cm^(−2)for hydrogen evolution reaction(HER)and 231 mV at 50 mA·cm^(−2)for oxygen evolution reaction(OER),and the corresponding overall water splitting requires only 1.48 V cell voltage at 10 mA·cm^(−2),which are superior to the most state-of-theart reported electrocatalysts.This work provides an innovative and feasible strategy to construct efficient electrocatalysts.