Indium-Containing Visible-Light-Driven (VLD) Photocatalysts for Solar Energy Conversion and Environment Remediation

Indium-containing visible-light-driven (VLD) photocatalysts including indium-containing oxides, indium-containing sulfides, indium-containing hydroxides, and other categories have attracted more attention due to their high catalytic activities for oxidation and reduction ability under visible light irradiation. This chapter will therefore concentrate on indium-containing nano-structured materials that demonstrate useful activity under solar excitation in fields concerned with the elimination of pollutants, partial oxidation and the vaporization of chemical compounds, water splitting, and CO2 reduction processes. The indium-containing photocatalysts can extend the light absorption range and improve the photocatalytic activity by doping, heterogeneous structures, load promoter, and morphology regulation. A number of synthetic and modification techniques for adjusting the band structure to harvest visible light and improve the charge separation in photocatalysis are discussed. In this chapter, preparation, properties, and potential applications of indium-containing nano-structured materials used as photocatalysis will be systematically summarized, which is beneficial for understanding the mechanism and developing the potential applications

Effects of the preparation method on the structure and the visible-light photocatalytic activity of Ag2CrO4

Silver chromate (Ag2CrO4) photocatalysts are prepared by microemulsion, precipitation, and hydrothermal methods, in order to investigate the effect of preparation methods on the structure and the visible-light photocatalytic activity. It is found that the photocatalytic activity of the prepared Ag2CrO4was highly dependent on the preparation methods. The sample prepared by microemulsion method exhibits the highest photocatalytic efficiency on the degradation of methylene blue (MB) under visible-light irradiation. The enhanced photocatalytic activity could be ascribed to the smaller particle size, higher surface area, relatively stronger light absorption, and blue-shift absorption edge, which result in the adsorption of more MB molecules, a shorter diffusion process of more photogenerated excitons, and a stronger oxidation ability of the photogenerated holes. Considering the universalities of microemulsion, precipitation, and hydrothermal methods, this work may also provide a prototype for the comparative study of semiconductor based photocatalysis for water purification and environmental remediation

溶胶凝胶-离子交换法制备具有可见光活性介孔AgInO2光催化剂 (Visible-light-driven Photocatalytic Activity of Mesoporous AgInO2 Synthesized by Sol-gel Combined Ion Exchange)

Design and fabrication of highly active photocatalysts under visible light irradiation are one of hotspots in the field of photocatalysis. In this paper, mesoporous AgInO2 nanostructures have been synthesized through a combined sol-gel and ion exchange process. Thermogravimetric analysis-differential scanning calorimeter (TGA-DSC), X-ray diffraction analysis (XRD), field emission scanning electron microscopy (FESEM), N2 adsorption-desorption and ultraviolet-visible (UV-vis) analysis technologies were used to investigate the effects of preparation condition on the microstructure of the AgInO2. The photocatalytic performances have been evaluated by degradation of the formaldehyde under visible light irradiation. The results demonstrate that the mesoporous AgInO2 is a delafossite structure with the uniform size about 200~500 nm and nitrogen adsorption-desorption type IV isotherms, the absorption edge of AgInO2 lies between 500nm and 600 nm in the visible light scope. As-synthesized AgInO2 exhibits remarkably high photocatalytic activity of 93.97% in decomposing formaldehyde for 180 min. These results provide a basic experimental process for preparation novel photocatalyst of AgInO2, which will possess a broad prospect in terms of the applications in improving indoor air quality.</p

Comprehensive Evaluation of the ‘Shixia’ Longan Quality under Postharvest Ambient Storage: The Volatile Compounds Played a Critical Part

Longan fruit generally undergoes rapid quality deterioration during the postharvest stage, with the manifestation of flavor loss as well as pronounced off-odor production. Nevertheless, the unapparent aroma makes people ignore the odor change in postharvest longan. Sensory analysis serves as an indispensable method combining instrumental detection and the perceptibility of human sensation in a comprehensive evaluation of quality during production and consumption. In this study, we established the evaluating data of the appearance, flavor, taste substances, volatile profiles, and deterioration of ‘Shixia’ longan throughout room-temperature storage using instrument assessment and descriptive measurements. Our results indicated that both the appearance state and the taste condition notably engendered confusion or trouble for consumers to judge under the quality transition period. Conversely, the development of odor was highly consistent with that of quality deterioration. Some unpleasant volatile substances including alcohol (ethanol), acid (acetic acid), and esters (acetic acid methyl ester and ethyl acetate) were probably the cause of off-odor during the storage. The result of the sensory evaluation also presents a more significant relevance between the overall quality and the odor. Generally, the work paved the way to reveal the importance of odor profiles for assessing the comprehensive quality condition of postharvest room-temperature stored longan

In-situ formatting donor-acceptor polymer with giant dipole moment and ultrafast exciton separation

Abstract Donor-acceptor semiconducting polymers present countless opportunities for application in photocatalysis. Previous studies have showcased their advantages through direct bottom-up methods. Unfortunately, these approaches often involve harsh reaction conditions, overlooking the impact of uncontrolled polymerization degrees on photocatalysis. Besides, the mechanism behind the separation of electron-hole pairs (excitons) in donor-acceptor polymers remains elusive. This study presents a post-synthetic method involving the light-induced transformation of the building blocks of hyper-cross-linked polymers from donor-carbon-donor to donor-carbon-acceptor states, resulting in a polymer with a substantial intramolecular dipole moment. Thus, excitons are efficiently separated in the transformed polymer. The utility of this strategy is exemplified by the enhanced photocatalytic hydrogen peroxide synthesis. Encouragingly, our observations reveal the formation of intramolecular charge transfer states using time-resolved techniques, confirming transient exciton behavior involving separation and relaxation. This light-induced method not only guides the development of highly efficient donor-acceptor polymer photocatalysts but also applies to various fields, including organic solar cells, light-emitting diodes, and sensors

Controllable synthesis of silicon/carbon microspheres alternating carbon and silicon shells for high-energy lithium-ion batteries

The poor cycling stability and huge volume change of silicon during the charge/discharge processes have seriously hindered the extensive application. In order to deal with address various challenges, silicon/carbon microspheres (SCM) are designed via nonsynchronous nucleation, hydrothermal coupling method and magnesium thermal reduction method. The silicon/carbon microspheres with two carbon shells (SCM-2) delivers the most enhanced initial charge capacity of 2455 mAh g(-1) at 0.1 C, and reveals the highest specific capacity of 2178 mAh g(-1) after 200 cycles and capacity retention of 98% after 500 cycles at 2 C. The SCM-2//LiCoO2 full cell can maintain high capacity of 159.2 mAh g(-1) and no capacity decay after 500 cycles at 0.1 C. It is demonstrated that the fabrication for silicon/carbon microspheres is a convenient and effective strategy to resolve the practical application silicon anode material in lithium-ion batteries

Controllable synthesis of silicon/carbon microspheres alternating carbon and silicon shells for high-energy lithium-ion batteries

The poor cycling stability and huge volume change of silicon during the charge/discharge processes have seriously hindered the extensive application. In order to deal with address various challenges, silicon/carbon microspheres (SCM) are designed via nonsynchronous nucleation, hydrothermal coupling method and magnesium thermal reduction method. The silicon/carbon microspheres with two carbon shells (SCM-2) delivers the most enhanced initial charge capacity of 2455 mAh g(-1) at 0.1 C, and reveals the highest specific capacity of 2178 mAh g(-1) after 200 cycles and capacity retention of 98% after 500 cycles at 2 C. The SCM-2//LiCoO2 full cell can maintain high capacity of 159.2 mAh g(-1) and no capacity decay after 500 cycles at 0.1 C. It is demonstrated that the fabrication for silicon/carbon microspheres is a convenient and effective strategy to resolve the practical application silicon anode material in lithium-ion batteries

A Comprehensive Analysis of Physiologic and Hormone Basis for the Difference in Room-Temperature Storability between &lsquo;Shixia&rsquo; and &lsquo;Luosanmu&rsquo; Longan Fruits

Although the effects of phytohormones (mainly salicylic acid) on the storability of longan fruit have been reported, the relationship between postharvest hormone variation and signal transduction and storability remains unexplored. The basis of physiology, biochemistry, hormone content and signalling for the storability difference at room-temperature between &lsquo;Shixia&rsquo; and &lsquo;Luosanmu&rsquo; longan fruit were examined. &lsquo;Luosanmu&rsquo; longan exhibited faster pericarp browning, aril breakdown and rotting during storage. &lsquo;Luosanmu&rsquo; pericarp exhibited higher malondialdehyde but faster decreased total phenolics, flavonoid, glutathione, vitamin C, catalase activity and gene expression. Higher H2O2 and malondialdehyde but lower glutathione, glutathione-reductase and peroxidase activities, while higher activities and gene expressions of polygalacturonase, &beta;-galactosidase and cellulose, lower covalent-soluble pectin, cellulose and hemicellulose but higher water-soluble pectin were observed in &lsquo;Luosanmu&rsquo; aril. Lower abscisic acid and methyl jasmonate but higher expressions of LOX2, JAZ and NPR1 in pericarp, while higher abscisic acid, methyl jasmonate and salicylic acid together with higher expressions of ABF, JAZ, NPR1 and PR-1 in &lsquo;Luosanmu&rsquo; aril were observed. In conclusion, the imbalance between the accumulation and scavenging of active oxygen in &lsquo;Luosanmu&rsquo; longan might induce faster lipid peroxidation and senescence-related hormone signalling and further the polymerization of phenolics in pericarp and polysaccharide degradation in aril