Yi-lei Li,Xu-jia Liu,Yun-biao Wang,Ying Liu,Rui-hong Liu,Hui-ying Mu,Ying-juan Hao,Xiao-jing Wang,Fa-tang Li
Adjusting the interfacial transport efficiency of photogenerated electrons and the free energy of hydrogen adsorption through interface engineering is an effective means of improving the photocatalytic activity of semiconductor photocatalysts. Herein, hollow ZnS/NiS nanocages with ohmic contacts containing Zn vacancy (V Zn -ZnS/NiS) are synthesized using ZIF-8 as templates. An internal electric field is constructed by Fermi level flattening to form ohmic contacts, which increase donor density and accelerate electron transport at the V Zn- ZnS/NiS interface. The experimental and DFT results show that the tight interface and V Zn can rearrange electrons, resulting in a higher charge density at the interface, and optimizing the Gibbs free energy of hydrogen adsorption. The optimal hydrogen production activity of V Zn -ZnS/NiS is 10,636 μmol h −1 g −1 , which is 31.9 times that of V Zn -ZnS. This study provides an idea for constructing sulfide heterojunctions with ohmic contacts and defects to achieve efficient photocatalytic hydrogen production.
Senyang Wang,Shi Tang,Mengting Hua,Yuxuan Chen,Dantian Zhang,Rao Fan,Ling Li
Raspberry-like double-core shell CdS@ZnS@NiS material was prepared to use a simple one-step hydrothermal method, and then coated uniformly on carbon nanofibers (CNFs), resulting in the formation of highly efficient counter electrode (CE) for Zn-Cu-In-Se (ZCISe) quantum dot sensitized solar cells (QDSSCs). The QDSSCs used CdS@ZnS@NiS/CNFs as CE reached power conversion efficiency (PCE) of 9.72%, which is higher than Cu 2 S/brass (8.42%). This result indicates the dual-core shell structure possesses better catalytic properties, which indicates that the raspberry-shaped double-core shell CdS@ZnS@NiS is a feasible competitor as CE material for QDSSCs.
Wang Yong,Qu Jianhang,Li Shufang,Dong Ying,Qu Jianying
We describe an electrochemical sensor for simultaneous determination of hydroquinone (HQ) and catechol (CC). A glassy carbon electrode (GCE) was modified with gold nanoparticles, L-cysteine, and ZnS/NiS@ZnS quantum dots using a layer-by-layer technique. The materials were characterized by X-ray diffractometry, field emission scanning electron microscopy, and electrochemical impedance and Fourier transform infrared spectroscopy. Cyclic voltammetry and differential pulse voltammetry revealed this modified GCE to represent a highly sensitive sensor for the simultaneous determination of HQ and CC. The anodic peak current for HQ at a working voltage of 80 mV (vs. Ag/AgCl) is related to its concentration in the 0.1 to 300 μM range (even in the presence of 0.1 mM of CC). The anodic peak current for CC at a working voltage of 184 mV is related to its concentration in the 0.5 to 400 μM range (even in the presence of 0.1 mM of HQ). The detection limits (at an S/N ratio of 3) are 24 and 71 nM for HQ and CC, respectively. The modified GCE was successfully applied to the determination of HQ and CC in aqueous solutions and gave satisfactory results.
A glassy carbon electrode was modified with gold nanoparticles, ZnS/NiS@ZnS quantum dots and L-cysteine and used for simultaneous determination of hydroquinone and catechol.
Senyang Wang,Shi Tang,Mengting Hua,Yuxuan Chen,Dantian Zhang,Rao Fan,Ling Li
Raspberry-like double-core shell CdS@ZnS@NiS material was prepared to use a simple one-step hydrothermal method, and then coated uniformly on carbon nanofibers (CNFs), resulting in the formation of highly efficient counter electrode (CE) for Zn-Cu-In-Se (ZCISe) quantum dot sensitized solar cells (QDSSCs). The QDSSCs used CdS@ZnS@NiS/CNFs as CE reached power conversion efficiency (PCE) of 9.72 %, which is higher than Cu 2 S/brass (8.42 %). This result indicates the dual-core shell structure possesses better catalytic properties, which indicates that the raspberry-shaped double-core shell CdS@ZnS@NiS is a feasible competitor as CE material for QDSSCs.