Hydrogen fuel is considered as the cleanest renewable resource and the primary alternative to fossil fuels for future energy supply. Sustainable hydrogen generation is the major prerequisite to realize future hydrogen economy. The electrocatalytic hydrogen evolution reaction (HER), as the vital step of water electrolysis to H2 production, has been the subject of extensive study over the past decades. In this comprehensive review, we first summarize the fundamentals of HER and review the recent state-of-the-art advances in the low-cost and high-performance catalysts based on noble and non-noble metals, as well as metal-free HER electrocatalysts. We systemically discuss the insights into the relationship among the catalytic activity, morphology, structure, composition, and synthetic method. Strategies for developing an effective catalyst, including increasing the intrinsic activity of active sites and/or increasing the number of active sites, are summarized and highlighted. Finally, the challenges, perspectives, and research directions of HER electrocatalysis are featured.

Recent Advances in Electrocatalytic Hydrogen Evolution Using Nanoparticles.

http://www.soilrem.ac.cn/files/project/20131031153245355.pdf

Photocatalytic degradation of tetracycline in aqueous solution by nanosized TiO2.

A multifunctional Au-coated TiO 2 nanotube array is made via synthesis of a TiO 2 nanotube array through a ZnO template, followed by deposition of Au particles onto the TiO 2 surface using photocatalytic deposition and a hydrothermal method, respectively. Such arrays exhibit superior detection sensitivity with high reproducibility and stability. In addition, due to possessing stable catalytic properties, the arrays can clean themselves by photocatalytic degradation of target molecules adsorbed to the substrate under irradiation with UV light into inorganic small molecules using surface-enhanced Raman spectroscopy (SERS) detection, so that recycling can be achieved. Finally, by detection of Rhodamine 6G (R6G) dye, herbicide 4-chlorophenol (4-CP), persistent organic pollutant (POP) dichlorophenoxyacetic acid (2,4-D), and organophosphate pesticide methyl-parathion (MP), the unique recyclable properties indicate a new route in eliminating the single-use problem of traditional SERS substrates and show promising applications for detecting other organic pollutants.

Multifunctional Au‐Coated TiO2 Nanotube Arrays as Recyclable SERS Substrates for Multifold Organic Pollutants Detection

Towards advanced aqueous dye removal processes: a short review on the versatile role of activated carbon.

Environmental problems have always received immense attention from scientists. Toxicants pollution is a critical environmental concern that has posed serious threats to human health and agricultural production. Heavy metals and pesticides are top of the list of environmental toxicants endangering nature. This review focuses on the toxic effect of heavy metals (cadmium (Cd), lead (Pb), copper (Cu), and zinc (Zn)) and pesticides (insecticides, herbicides, and fungicides) adversely influencing the agricultural ecosystem (plant and soil) and human health. Furthermore, heavy metals accumulation and pesticide residues in soils and plants have been discussed in detail. In addition, the characteristics of contaminated soil and plant physiological parameters have been reviewed. Moreover, human diseases caused by exposure to heavy metals and pesticides were also reported. The bioaccumulation, mechanism of action, and transmission pathways of both heavy metals and pesticides are emphasized. In addition, the bioavailability in soil and plant uptake of these contaminants has also been considered. Meanwhile, the synergistic and antagonistic interactions between heavy metals and pesticides and their combined toxic effects have been discussed. Previous relevant studies are included to cover all aspects of this review. The information in this review provides deep insights into the understanding of environmental toxicants and their hazardous effects.

Heavy Metals and Pesticides Toxicity in Agricultural Soil and Plants: Ecological Risks and Human Health Implications.

The photocatalytic degradation of Rhodamine B (RhB) was carried out using TiO2 supported on activated carbon (TiO2-AC) under microwave irradiation Composite catalyst TiO2-AC was prepared and characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) In the process of microwave-enhanced photocatalysis (MPC), RhB (30 mg/L) was almost completely decoloured in 10 min, and the mineralization efficiency was 960% in 20 min The reaction rate constant of RhB in MPC using TiO2-AC by pseudo first-order reaction kinetics was 416 times of that using Degussa P25 Additionally, according to gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/mass spectrometry (LC/MS) identification, the major intermediates of RhB in MPC included two kinds of N-de-ethylation intermediates (N, N-diethyl-N'-ethyl-rhodamine (DER)), oxalic acid, malonic acid, succinic acid, and phthalic acid, maleic acid, 3-nitrobenzoic acid, and so on The degradation of RhB in MPC was mainly attributed to the destruction of the conjugated structure, and then the intermediates transformed to acid molecules which were mineralized to water and carbon dioxide

http://www.jesc.ac.cn/jesc_cn/ch/reader/create_pdf.aspx?file_no=2009210222

Microwave photocatalytic degradation of Rhodamine B using TiO2 supported on activated carbon: mechanism implication.

Pollution of soil environment has become a serious problem in many countries. Repeated application of bordeaux mixture and pyrethroids insecticides have led to elevated copper (Cu) and pyrethroids concentrations in vineyard surface soils. Therefore, it is recommended to evaluate the combined effect of copper and pyrethroids on soil enzymes. Our aim was to get a more comprehensive understanding of the effects of Cu and cypermethrin on the soil catalase, and to provide more information about the potential ecological risk of chemicals on the soil ecosystem. The dried and sieved soil sample was first thoroughly mixed with aqueous solution of CuSO4 5H2O, and acetone solution of cypermethrin according to the orthogonal design, and then incubated at 25°C for 35 days. Five concentration levels for each pollutant (Cu and cypermethrin) were studied. Control without any artificial contamination received the same amount of distilled water and acetone. Each test was conducted with three replications. Moisture in the incubated soil samples was kept at 60% of the full soil water holding capacity by weighing daily. Catalase activity was determined by back-titrating residual H2O2 with KMnO4 after 7, 14, 21, 28, and 35 days. Data treatment was essentially based on analysis of the variance test. During the incubation time, soil catalase activity was lower than the control samples and the result ranged from 70.64% to 100%, except for that of the two samples S6 and S13. The catalase activity in all samples was declined after application of Cu, without addition of cypermethrin. While the concentration of cypermethrin ranged from 0 to 150 mg kg–1, without the addition of Cu, the variety of catalase activity was as follows: restrained–activated–restrained. The combined effect of cypermethrin and Cu on soil catalase activity depends largely on the concentration of pollutants. The presumable explanation of the result that the catalase was inhibited by single Cu addition was due to: (1) complexation of the substrate, (2) combination with the protein-active groups of the enzymes, or (3) reaction with the enzyme–substrate complex. In our study, there were some differences in the catalase when soil samples were treated with a different concentration of cypermethrin. This is possibly related to the protect mechanism of soil catalase. In addition, the combined effect of cypermethrin and Cu on catalase activity is stronger than single cypermethrin, while weaker than single Cu. One of the possible explanations of this phenomenon is related with the interaction between cypermethrin and Cu. Another may be related to bioavailability. The combined effect of cypermethrin and Cu on soil catalase activity depends largely on the concentration of the pollutants. The magnitude and type of interaction may be strongly dependent on the level of response and the relative proportion of the components in the mixture. These factors should therefore be considered in risk assessments and in the setting of soil quality criteria. Generally speaking, the influence of pesticides and heavy metals on soil is a long-term process and is closely related to soil characteristics. Much more should be done to clearly understand the mechanism of interaction between cypermethrin and Cu on soil.

Combined effect of cypermethrin and copper on catalase activity in soil

The influence of coexisting copper (Cu) ion on the degradation of pesticides pyrethroid cypermethrin and cyhalothrin in soil and photodegradation in water system were studied. Serial concentrations of the pesticides with the addition of copper ion were spiked in the soil and incubated for a regular period of time, the analysis of the extracts from the soil was carried out using gas chromatography (GC). The photodegradation of pyrethroids in water system was conducted under UV irradiation. The effect of Cu2+ on the pesticides degradation was measured with half life (t0.5) of degradation. It was found that a negative correlation between the degradation of the pyrethroid pesticides in soil and Cu addition was observed. But Cu2+ could accelerate photodegradation of the pyrethroids in water. The t0.5 for cyhalothrin extended from 6.7 to 6.8 d while for cypermethrin extended from 8.1 to 10.9 d with the presence of copper ion in soil. As for photodegradation, t0.5 for cyhalothrin reduced from 173.3 to 115.5 min and for cypermethrin from 115.5 to 99.0 min. The results suggested that copper influenced the degradation of the pesticides in soil by affecting the activity of microorganisms. However, it had catalyst tendency for photodegradation in water system. The difference for the degradation efficiency of pyrethroid isomers in soil was also observed. Copper could obviously accelerate the degradation of some special isomers.

Cheng Sun

Papers

Microwave photocatalytic degradation of Rhodamine B using TiO2 supported on activated carbon: mechanism implication.

Combined effect of cypermethrin and copper on catalase activity in soil

Effect of copper on the degradation of pesticides cypermethrin and cyhalothrin.

Electrosynthesis of poly(aniline-co-p-aminophenol) having electrochemical properties in a wide pH range

In situ growth of N-doped carbon coated CoNi alloy with graphene decoration for enhanced HER performance