Photoelectrochemical Immunosensor Array Based on Thioglycolic Acid Capped CdS Quantum Dots for Multiplexed Detection of Veterinary Drug Residues

A photoelectrochemical immunosensor based on multi‐electrode array was developed for simultaneous and sensitive determination of veterinary drug residues. In this system, poly(dimethyldiallylammonium chloride) (PDDA), Au nanoparticles (Au NPs) and thioglycolic acid (TGA)‐capped CdS quantum dots (QDs) were layer‐by‐layer assembled onto the home‐made Au electrode array. The assembling process of the (CdS/PDDA/Au NPs/PDDA)_n multilayer was characterized by electrochemical impedance spectroscopy. And then the antibodies for clenbuterol (CB), ractopamine (RAC) and chloramphenicol (CAP) were covalently immobilized onto the Au electrode array by 1‐ethyl‐3‐(3‐dimethylaminopropyl) carbodiimide (EDC) coupling reaction, respectively. The concentrations of CB, RAC and CAP were measured based on the photoelectrochemical effects of CdS QDs. Under the optimal conditions, the limits of detection (LOD) for CB, RAC and CAP were 25, 50 and 2.2 pg/mL (3Δ), respectively, with acceptable recovery over the range of 95.40%–105.5% in pig liver samples. All results indicate that the immunosensor array system has potential application for practical, effective and high throughput analysis of veterinary drugs residues.     

Photoelectrochemical Detection of Glucose by Using an Enzyme‐Modified Photoelectrode

A new photoelectrochemical method for the determination of glucose based on the photoelectrochemical effect of poly(thionine) photoelectrode to hydrogen peroxide (H₂O₂) was reported. The H₂O₂‐sensitive photoelectrode was fabricated by electropolymerizing thionine on the surface of ITO electrode. And then glucose oxidase was immobilized on the photoelectrode via the aid of chitosan enwrapping, forming an enzyme‐modified photoelectrode. The photoelectrode was employed as an electron acceptor; H₂O₂ from the catalytic reaction of enzyme was employed as an electron donor, developing an analytical method of glucose without hydrogen peroxidase. In the paper, the photoelectrochemical effects of photoelectrode to H₂O₂ and glucose were studied. The effects of the bias voltage and the electrolyte pH on the photocurrent were investigated. The linear response of glucose concentrations ranged from 0.05 to 2.00 mmol/L was obtained with a detection limit of 22.0 µmol/L and sensitivity of 73.2 nA/(mmol·L^?1). The applied feasibility of method was acknowledged through monitoring the glucose in practical samples.     

锂－氧化铜电池反应机理──Ⅲ．放电电流对阴极过程的影响

利用光电化学方法和Ｘ射线衍射分析方法，研究了锂－氧化钢电池阴极还原反应．发现采用不同电流密度放电，该电池阴极过程有较大差别：放电电流密度较小时，电化学嵌入反应是主要的阴极过程；随放电电流密度的增大，经典的还原反应以越来越大的比例加入到放电过程中来．据此解释了文献报道中存在的一些矛盾现象．     

中性介质中铜缓蚀剂的成膜过程

使用光电化学与电化学石英晶体微天平联用（PECQCM）技术对中性介质铜缓蚀剂成膜过程进行了现场研究．结果表明，在中性Na2SO4溶液中钝化型缓蚀剂Na2OrO4对Cu成膜生长有抛物线规律，而由于Cl-的影响，在中性NaCl溶液中，该缓蚀剂膜生长曲线为折线型．沉淀型缓蚀剂Na2SiO3在Na2SO4溶液中的铜晶振电极上不成膜，而在NaCl溶液中可成膜．     

Photocurrent characteristics in Cu2O/Pt and Cu2O/TiO2 photoelectrochemical cells in aqueous and non-aqueous electrolytes

Photocurrent characteristics of the Cu₂O/Pt and Cu₂O/TiO₂ photoelectro-chemical cells have been presented. In aqueous solution, a slow deterioration of power output occurs approximately at the rate of 50% per day. Operation in non-aqueous solutions (acetonitrile and ethanol) also produced a deterioration of power output. However in ethanol, it was found that the deterioration reversed itself and a new cycle of deterioration and rejuvenation began. These suggest that the deterioration is not due to a chemical reduction process at the electrode surface but other factors such as migration of charged defect centres in the depletion layer or chemical reaction on the electrode surface.     

PHOTOELECTROCHEMISTRY OF ELECTRODEPOSITED POLYCRYSTALLINE CuInSe_2 THIN FILMS (Ⅰ)——ELECTRODEPOSITION OF CuInSe_2 FILMS

Electrodeposition of CulnSe, was investigated in acidic solutions containing Cu~(2+), In~(3+) and HSeO_2~+ ions. The electrodeposition condition was optimized with the aim of obtaining uniform thin films on titanium substrate. The mechanism of the electrodeposition process is discussed. Structure analysis of the deposited film shows a typical polycrystalline chalcopyrite structure, good crystallinity and homogeneous dispersion. The photoelectrochemical cells made of these kinds of deposited films in polysulfide redox solution give distinct photoresponse.     

Transition metal dichalcogenide thin films for solar hydrogen production

In the last three decades, transition metal dichalcogenides (TMDs) have been extensively studied for electronic, photonic, and energy applications. Different efforts are directed to find a holy grail of efficient and economically feasible materials that could be simple in production and available on a large scale. The interest in TMDs (MoS₂, WS₂, MoSe₂, WSe₂) stems from their suitable electronic structure for efficient solar light absorption and simple exfoliation technique of 2D crystallites due to the van der Waals bonding of these materials. This led to various designs and combinations of 2D single layers that could form heterojunctions and multijunctions for efficient light absorption, charge carrier generation/separation, and its transfer in optoelectronic and energy harvesting devices. Herein, TMD thin films are reviewed as photoelectrodes for solar hydrogen evolution and compared to that of other more developed materials.     

湿化学法制备硅纳米线阵列及其光电化学产氢性能分析

为了探究不同方法条件下制备的硅纳米线阵列电极产氢性能异同,文中分别采用了两步金属辅助催化无电刻蚀法、一步金属辅助催化无电刻蚀法以及阳极氧化法来制备硅纳米线阵列用作为光电分解水电池光阴极材料。通过FESEM、XRD和UVVis-IR DRS等手段对实验样品的形貌、晶型、减反性表征,发现相比于其他2种方法所得硅纳米线样品,两步金属辅助催化无电刻蚀法制备的硅纳米线结构晶型保持更好,表面缺陷更少。光电化学测试表明两步金属辅助催化无电刻蚀法制备的硅纳米线光电化学性能表现最优,其光电流密度值是一步法的4倍,阳极氧化法的40倍;转移电荷电阻仅是一步法制备的硅纳米线阵列阻值的1/3,阳极氧化法制备的1/1 000。     

Moving Graphitic Carbon Nitride from Electrocatalysis and Photocatalysis to a Potential Electrode Material for Photoelectric Devices

Carbon nitride (g‐CN) has attracted significant interest in the last years as a robust, low‐cost alternative to metal‐based materials in different fields due to its low price, environmentally benign character, simple synthesis and tunable properties. In particular, g‐CN demonstrates promising activity in energy‐related applications such as photo and heterogeneous catalysis, batteries and electrolysis. However, while g‐CN is already well‐established as a photocatalyst, its utilization in (opto)electronic devices is still at an early stage. This Focus Review concentrates on the utilization of g‐CN in solar and photoelectrochemical cells, electrolyzers and light emitting diode alongside the recap of new synthetic approaches. This review is expected to provide useful insights into the design and fabrication of g‐CN based photoelectronic devices as well as g‐CN working principles, including the main challenges toward its integration in optoelectronic devices.     

Boosting the Photoactivity of BiVO4 Photoanodes by a ZnCoFe-LDH Thin Layer for Water Oxidation

Monoclinic bismuth vanadate (BiVO₄) has been used as an efficient photoanode material for photoelectrochemical water oxidation owing to its suitable band gap and nontoxicity. Nevertheless, the practical application of BiVO₄ photoanode has been severely limited by the surface charge recombination and sluggish kinetic, which leads to the obtained photoactivity of BiVO₄ is much lower than its theoretical value. In this case, ZnCoFe-LDH thin layer is conformally decorated on the porous BiVO₄ photoanode through a simple electrodeposition process. The results show that a boosted photoactivity and a remarkably enhanced photocurrent density (3.43 mA cm⁻² at 1.23 V_RHE) are attained for BiVO₄/ZnCoFe-LDH. In addition, the optimized BiVO₄/ZnCoFe-LDH photoanode exhibits significant negative shift in the onset potential (0.51 V_RHE to 0.21 V_RHE), promotes charge separation efficiency (49.3% to 60.4% in the bulk, 29.6% to 61.9% on the surface at 1.23 V_RHE) and enhanced IPCE efficiency (25.5% to 54.7% at 425 nm) compared with that of bare BiVO₄ photoanode. It is demonstrated that the boosted photoactivity of BiVO₄/ZnCoFe-LDH photoanode is mainly ascribed to the synergy effects of the formation of p-n heterojunction between ZnCoFe-LDH and BiVO₄ to accelerate the photogenerated charge transfer and separation, broaden light absorption, as well as promote the surface water oxidation kinetics.