Recent advances of doped graphite carbon nitride for photocatalytic reduction of CO2: a review

CO₂ is the main gas that causes the “greenhouse effect,” and it is also a rich carbon resource. The photocatalytic conversion of CO₂ into fuel not only relieves the pressure brought by the environment pollution, but also is promising way to achieve the carbon cycle and address the problem of energy shortage. It is essential to design efficient photocatalysts for the practical application of photocatalytic CO₂ conversion. Doped graphite carbon nitride (g-C₃N₄) has a reduced bandgap, increased light absorption and effective charge separation and transfer efficiency. Recently, its application has been extended to the field of photocatalytic reduction of CO₂. In this review, we first discuss the basic principles of photocatalytic reduction of CO₂, then focus on the application of g-C₃N₄ doped with different elements in the photocatalytic reduction of CO₂ in recent years, and then summarize different doping methods. Finally, challenges and opportunities are presented, and potential solutions are proposed for future research.

     

不同高度柔性植被对坡面流水动力特性的影响

基于系列坡面流试验,研究了柔性植被的高度(4 cm,8 cm和15 cm)对坡面流水动力特性的影响.研究表明:覆盖率相同时,4 cm植被阻水效果最好,15cm最差,而该差异随着坡度增大而减小.4 cm和8 cm植被覆盖时,水流阻力系数随雷诺数增加先减小后增加,这是由于雷诺数较小时水流阻力主要以床面阻力为主,雷诺增大时主要以植被阻力为主.另外,通过染色剂法测得光滑床面平均流速修正系数为0.2～0.4,有植被覆盖床面为0.4～0.8,且修正系数随平均流速增大而增大.     

FeCuNbSiB软磁粉/硅橡胶应力敏感复合材料的制备及其影响因素

以FeCuNbSiB软磁粉为功能填充粒子,三元嵌段有规共聚硅橡胶为基体,采用机械共混和精密铸压热成型方法制备了FeCuNbSiB软磁粉/硅橡胶柔性复合材料薄膜(简称"FeCuNbSiB/SiR复合薄膜")。分别观测了填充粒子FeCuNbSiB软磁粉及其复合薄膜的显微形貌,重点研究了FeCuNbSiB软磁粉的热处理、含量、粒径及其硅橡胶复合薄膜厚度等因素对复合薄膜力敏特性的影响。研究结果表明:FeCuNbSiB软磁粉微观结构呈多角片状,当粒径小于30μm,软磁粉在硅橡胶基体中具有良好的分散性;经480℃热处理1h后的FeCuNbSiB软磁粉的磁性能显著提高,当其体积分数为27.5vol%,粒径10μm且复合薄膜厚度为200±2μm时,FeCuNbSiB/SiR复合薄膜具有最佳的力敏特性和良好的应力阻抗重复稳定性,可用作新型柔性力传感器敏感元的开发。     

血管内超声图像的仿真

血管内超声(IVUS)图像的仿真有助于检验诸如图像分割等图像处理算法的性能.提出一种IVUS图像仿真的方法.该方法在极坐标图像生成模型中引入环晕、导丝伪影,并分别对粥样硬化斑块的纤维、脂质、钙化三个区域进行模拟,实现静态图像的仿真;运用血管随心脏搏动的变化规律,实现序列图像的仿真.通过对15例真实IVUS图像、每例各50次的实验表明,相对于传统的极坐标图像生成模型,该方法仿真的图像与真实图像的相关系数提高了56.9%,互信息提高了24.3%,其仿真效果更加接近真实图像.     

The preparation,and applications of g-C<Subscript>3</Subscript>N<Subscript>4</Subscript>/TiO<Subscript>2</Subscript> heterojunction catalysts—a review

In recent years, more and more attention has been paid in the research of heterojunction catalysts, due to their better catalytic ability than that of single component catalysts. Up to now, many kinds of heterojunction catalysts have been reported, such as Bi₂O₃/Bi₂WO₆, WO₃/BiVO₄, SnO₂/TiO₂, CdS/TiO₂, Ta₃N₅/Pt/IrO₂ and so on, among which the heterojunction catalyst composed of g-C₃N₄ and TiO₂ has been studied tremendously recently, due to the high activity, high thermal and chemical stability, and well matched energy structure of them. Up to now, many methods have been explored for the synthesis of g-C₃N₄/TiO₂ heterojunction catalysts, such as ball milling of g-C₃N₄ and TiO₂, hydrothermal growth of TiO₂ on g-C₃N₄ and so on. In this review, the recent researches on the synthesis of g-C₃N₄/TiO₂ catalysts were summarized. Moreover, the applications of g-C₃N₄/TiO₂ catalysts in the field of photocatalysis were detailedly introduced.     

Rapid simultaneous determination of 14 sulfonamides in wastewater by liquid chromatography tandem mass spectrometry

This paper describes a rapid method for the determination of 14 kinds of sulfonamides (SAs) in wastewater using SPE, and LC-MS/MS with positive ESI (ESI(+)) and selected reaction monitoring (SRM) mode. The SPE was performed on an Oasis hydrophilic-lipophilic-balanced (HLB) cartridge. Chromatographic separation on a C18 column was achieved using a binary eluent containing methanol and water with 0.2% formic acid. Typical recoveries of the analytes ranged from 22.3 to 87.0% at a fortification level of 100 ng/L. The LODs in wastewater except sulfathiazole (3 ng/L) could be detected and quantified at levels as low as 1 ng/L. Finally, the method was applied to water from the municipal outlet and the aquaculture wastewater effluent. Sulfamethazine (SM(2)), sulfamethoxypyridazine (SMP), and sulfamethoxazole (SMZ) were most frequently found in wastewater in a concentration range between 1.2 and 31.7 ng/L.     

Anti-Inflammatory Action and Mechanisms of Resveratrol

Resveratrol (3,4′,5-trihy- droxystilbene), a natural phytoalexin polyphenol, exhibits anti-oxidant, anti-inflammatory, and anti-carcinogenic properties. This phytoalexin is well-absorbed and rapidly and extensively metabolized in the body. Inflammation is an adaptive response, which could be triggered by various danger signals, such as invasion by microorganisms or tissue injury. In this review, the anti-inflammatory activity and the mechanism of resveratrol modulates the inflammatory response are examined. Multiple experimental studies that illustrate regulatory mechanisms and the immunomodulatory function of resveratrol both in vivo and in vitro. The data acquired from those studies are discussed.     

Preparation of NiCoP-decorated g-C3N4 as an efficient photocatalyst for H2O2 production

Research on Chemical Intermediates - The development of high-efficiency economic photocatalyst for H2O2 production is of great significance for renewable energy technologies. Here, we use a...     

Innovative approach for the electrochemical detection of non-electroactive organophosphorus pesticides using oxime as electroactive probe

An innovative approach for sensitive and simple electrochemical detection of non-electroactive organophosphorus pesticides (OPs) was described in this report. The novel strategy emphasized the fabrication of an oxime-based sensor via attaching pralidoxime (PAM) on graphene quantum dots (GQDs) modified glassy carbon electrode. The introduction of GQDs significantly increased the effective electrode area, and then enlarged the immobilization quantity of PAM. Thus, the oxidation current of PAM was obviously increased. Relying on the nucleophilic substitution reaction between oxime and OPs, fenthion was detected using PAM as the electroactive probe. Under optimum conditions, the difference of oxidation current of PAM was proportional to fenthion concentration over the range from 1.0 × 10⁻¹¹ M to 5.0 × 10⁻⁷ M with a detection limit of 6.8 × 10⁻¹² M (S/N = 3). Moreover, the favorable detection performance in water and soil samples heralded the promising applications in on-site OPs detection.     

A Square‐Planar Tetracoordinate Oxygen‐Containing Ti4O17 Cluster Stabilized by Two 1,1′‐Ferrocenedicarboxylato Ligands

By introducing steric constraints into molecular compounds, it is possible to achieve atypical coordination geometries for the elements. Herein, we demonstrate that a titanium‐oxo cluster [{Ti₄(μ₄‐O)(μ₂‐O)₂}(OPrⁱ)₆(fdc)₂], which possesses a unique edge‐sharing Ti₄O₁₇ octahedron tetramer core, is stabilized by the constraints produced by two orthogonal 1,1′‐ferrocenedicarboxylato (fdc) ligands. As a result, a square‐planar tetracoordinate oxygen (ptO) can be generated. The bonding pattern of this unusual anti‐van’t Hoff/Le Bel oxygen, which has been probed by theoretical calculations, can be described by two horizontally σ‐bonded 2p_x and 2p_y orbitals along with one perpendicular nonbonded 2p_z orbital. While the two ferrocene units are separated spatially by the ptO with an Fe???Fe separation of 10.4 Å, electronic communication between them still takes place as revealed by the cluster’s two distinct one‐electron electrochemical oxidation processes.