Optimization of N2/Ar gas flow ratio for the realization of nitrogen-doped p-type ZnCdO thin films synthesized by RF magnetron sputtering

Nitrogen doped ZnCdO films [ZCO:N] have been grown on quartz substrates by radio frequency (RF) reactive magnetron sputtering technique, and the effect of the ratio of nitrogen to argon gas flow [N₂:Ar] on their electrical, microstructure and optical properties were investigated by Hall effect, energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), transmission electron microscope (TEM), optical absorbance and photoluminescence (PL) measurements. The results indicate that all the ZCO:N films are of hexagonal wurtzite structure with highly (002) preferential orientation. As the N₂:Ar increases from 0:1 to 4:1, the absorption edge for the samples exhibits blue shift. Hall effect measurement results indicate that the N₂:Ar exerts an immense influence on the p-type conduction conversion for ZCO:N film. It is found that ZCO:N film deposited at the N₂:Ar of 1:2 shows the optimal p-type behavior, which has a carrier concentration of 1.10×10¹⁷ cm⁻³, a mobility of 3.28 cm²V⁻¹s⁻¹ and a resistivity of 17.3 Ω cm. Compared with the other samples, ZCO:N film fabricated at the relatively lower N₂:Ar possesses the superior crystal quality, luminescent and electrical properties. Additionally, a possible mechanism of p-type conduction for ZCO:N film was discussed in this work.     

Sole Chemical Confinement of Polysulfides on Nonporous Nitrogen/Oxygen Dual‐Doped Carbon at the Kilogram Scale for Lithium–Sulfur Batteries

The exploration of inexpensive, facile, and large‐scale methods to prepare carbon scaffolds for high sulfur loadings is crucial for the advancement of Li–S batteries (LSBs). Herein, the authors report a new nitrogen and oxygen in situ dual‐doped nonporous carbonaceous material (NONPCM) that is composed of a myriad of graphene‐analogous particles. Importantly, NONPCM could be fabricated on a kilogram scale via inexpensive and green hydrothermal‐carbonization‐combined methods. Many active sites on the NONPCM surface are accessible for the efficient surface‐chemistry confinement of guest sulfur and its discharge product; this confinement is exclusive of physical entrapment, considering the low surface area. Electrochemical examination demonstrates excellent cycle stability and rate performance of the NONPCM (K)/S composite, even with a sulfur loading of 80 or 90 wt%. Hence, the scaffolds for LSBs exhibit potential for industrialization through further optimization and expansion of the present synthesis.     

四元掺杂电致变色薄膜材料的制备及其性能的研究

用溶胶 凝胶法首次制备了组分为 WO3、TiO2、CrO3、PEO的四元掺杂电致变色薄膜材料,得到了较佳的组分配比,用 TG DTA,XRD 研究薄膜材料的结构变化,推断出最佳热处理温度。循环伏安和可见光透过率测试表明该薄膜材料有较好的电化学性能和阴极着色效应,可以作为电致变色器件中的阴极电致变色层薄膜材料。     

轴向气相沉积法F掺杂对玻璃的腐蚀作用

利用轴向气相沉积法制备高掺F光纤预制棒过程中,CF4作为掺F源,在高温状态下,对所接触到的玻璃器皿产生腐蚀作用。本文研究了CF4气体在沉积过程对喷灯的腐蚀规律;CF4气体在玻璃化过程中对玻璃化炉的腐蚀。     

Iron doped mesoporous cobalt phosphide with optimized electronic structure for enhanced hydrogen evolution

We report a self-supporting electrode fabricated by covering iron doped mesoporous cobalt phosphide film on carbon cloth substrate (meso-Fe_xCo_1-xP/CC) for hydrogen evolution reaction (HER). In acidic and alkaline electrolytes, the electrode exhibited excellent catalytic activity and fast kinetics towards the HER, only requiring small overpotentials of 61 mV and 67 mV to drive 10 mA cm^?2, respectively. The superior electrocatalytic activity is attributed to the mesoporous structure with high specific surface area (147.5 m² g^?1) and doping of Fe atom. The mesoporous structure grown on the conductive carbon cloth substrate enables the fully exposure of active sites and the rapid penetration of electrolyte. Additionally, density functional theory (DFT) calculation reveals that the doping of Fe enhances the adsorption of H atoms by shifting the d-band center of Co. Meanwhile, the introduction of Fe lowers the energy barrier for water dissociation, which accelerates the catalytic kinetics in alkaline electrolyte.     

Role of V doping in core–shell heterostructured Bi2Te3/Sb2Te3 for hydrogen evolution reaction

Non-noble metal-based materials as low-cost hydrogen evolution reaction (HER) catalysts are key materials for sustainable hydrogen energy production. Bismuth and antimony chalcogenides are among the hopeful candidates to achieve this goal. In this work, a V-doped Sb₂Te₃ encapsulated Bi₂Te₃ core-shell electrocatalyst (Bi₂Te₃/V_x-Sb₂Te₃) has been synthesized by a two-step solvothermal method. V doping adjusts the electronic structure of catalyst, dramatically enhances electric double layer capacitance (C_dl) of the catalyst, decreases charge transfer resistance (R_ct) of the catalyst and increases carrier concentration of the catalyst. Therefore, the V doping method increases the active sites on the surface of the material, and promotes the charge transfer and electron transport in the HER process. In addition, V doping can also adjust the hydrophilicity of the material surface, promote the release of hydrogen, and quickly re-expose the active sites. Bi₂Te₃/V_x-Sb₂Te₃ electrocatalysts exhibit brilliant HER activity and high stability in both acidic and alkaline electrolytes. This study uses the strategy of V doping to control the electronic structure of materials, which will provide suggestions for the design and preparation for other high-activity catalysts.     

Nitrogen-phosphorus doped starch carbon enhanced biohydrogen production

To solve the thermodynamic limitations on the hydrogen (H₂) yield by dark fermentation (DF), the conductive carbons are usually used to mediate the H₂-DF.In this work, the nitrogen (N)-phosphorus (N) doped starch carbon (NPSC) was prepared and characterized to investigate its influence on H₂-DF. NPSC effectively raise H₂ yield compared with starch-derived carbon (SC). The optimal dosage of SC (400 mg/L) and NPSC (600 mg/L) caused the highest H₂ yield of 219.5 and 261.2 mL/g glucose, respectively, being higher than the control yield (161.4 mL/g glucose). Factually, compared with the control group without any carbon, NPSC optimized the microbial community structure and increased the abundance of C. butyricum from 19.09% to 30.87%. This fact increased the shift of metabolic pathway to butyric acid evolution, thereby promoting the substrate conversion level to H₂.     

Interstitial P‐Doped CdS with Long‐Lived Photogenerated Electrons for Photocatalytic Water Splitting without Sacrificial Agents

Photocatalytic hydrogen evolution from pure water is successfully realized by using interstitial P‐doped CdS with rich S vacancies (CdS‐P) as the photocatalyst in the absence of any electron sacrificial agents. Through interstitial P doping, the impurity level of S vacancies is located near the Fermi level and becomes an effective electron trap level in CdS‐P, which can change dynamic properties of photogenerated electrons and thus prolong their lifetimes. The long‐lived photogenerated electrons are able to reach the surface active sites to initiate an efficient photocatalytic redox reaction. Moreover, the photocatalytic activity of CdS‐P can be further improved through the loading of CoP as a cocatalyst.     

Hydrogen ion supercapacitor cell construction and rational design of cell structure

A hydrogen ion supercapacitor cell was constructed with an electrochemical double‐layer carbon material as positive electrode and an electrochemical hydrogen storage composite material as negative electrode. The electrochemical performances of both electrodes and hybrid device were investigated by varying of the mass ratio of positive and negative electrode. It was found to be that both electrodes went through the different hydrogen ion storage processes and the capacity of this hybrid supercapacitor was highly correlated with the negative to the positive electrode ratio. The highest capacity was achieved at ratio of 1:7; further increasing of this ratio may downgrade the performance of the hybrid system. With this optimized ratio, the hybrid device demonstrated good electrochemical performance.