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The maximum FEHCOO− acquired on Bi2S3/CNTs is about 99.3%, and kept over 91% in a wide potential window from −0.71 to −1.31 V vs. RHE.

Exploring highly efficient catalyst is the key for integration of photocatalysis and peroxymonosulfate (PMS) activation. Herein, WC/Bi2WO6 nanocomposites were judiciously constructed by anchoring the non-noble metal plasmonic WC nanocrystals onto the surface of ultrathin Bi2WO6 nanosheets to activate PMS for efficient photodegradation of bisphenol A (BPA). The prepared WC/Bi2WO6 nanocomposites possess abundant heterojunction interface, resulting in excellent photoabsorption capability, interfacial charge transfer dynamics, and charge carrier concentration. As expected, WC/Bi2WO6 nanocomposites exhibit superior catalytic activity and stability in PMS activation toward BPA degradation with removal efficiency of 97.4%, which is higher than that of Bi2WO6. The content of WC nanocrystals are critical to tune the catalytic activity of the nanocomposites. The intermediates and degradation pathways were determined through LC-MS/MS analysis. Finally, the reaction mechanism was systematically elucidated based on the active species detection, charge transfer dynamics, and band structures. The desirable photocatalytic performances can be ascribed to the constructional heterojunction between the WC nanocrystals and Bi2WO6 nanosheets, which can efficiently enhance the photoabsorption capability, heighten the interfacial charge transfer ability, and ameliorate the charge carrier concentration. This study provides some insights to construct highly efficient photocatalyst modification with non-noble metal based plasmonic materials for environmental remediation.

The sulfate-reducing mediate microbial fuel cell (MFC) shows advantages in treating recalcitrant flowback water (FW) from shale gas extraction, but the stability under fluctuant concentrations of sulfate in FW remains unknown. Herein, we investigated the impact of fluctuant sulfate concentrations on the performance of FW treatment in MFCs. Sulfate concentration showed a significant role in the MFC treating FW, with a COD removal of 69.8 ± 9.7% and a peak power density of 2164 ± 396 mW/m

The widespread application of quaternary ammonium compounds (QAC) has posed a serious hazard to the environment and human being, and high concentration of Cl

The combination of peroxymonosulfate (PMS) activation and photocatalysis has proven to be effective for organic contaminants treatment. However, the construction of an efficient catalytic material is an important challenge. Herein, novel Bi2WO6/BiOCl heterojunction nanocomposites were successfully designed and fabricated using a facile and effective strategy for bisphenol A (BPA) photodegradation with PMS activation. The well-designed heterojunction with improvement of the contact area and interface microstructure was obtained through in situ growth of the Bi2WO6 on the surface of BiOCl. The Bi2WO6/BiOCl nanocomposites exhibit excellent catalytic performance in PMS activation for BPA degradation under visible light irradiation. A possible photocatalytic reaction mechanism was systematically revealed. The excellent catalytic performance is mainly attributed to the strong interaction between Bi2WO6 and BiOCl, resulting in an enhanced photoabsorption and a more efficient interfacial charge separation and transfer. This paper provides a novel strategy to design efficient catalytic materials for organic contaminants remediation with PMS activation.

The high volume of flowback water (FW) generated during shale gas exploitation is highly saline, and contains complex organics, iron, heavy metals, and sulfate, thereby posing a significant challenge for the environmental management of the unconventional natural gas industry. Herein, the treatment of FW in a sulfur-cycle-mediated microbial fuel cell (MFC) is reported. Simultaneous removal efficiency for chemical oxygen demand (COD) and total iron from a synthetic FW was achieved, at 72 ± 7% and 90.6 ± 8.7%, respectively, with power generation of 2667 ± 529 mW/m3 in a closed-circuit MFC (CC-MFC). However, much lower iron removal (38.5 ± 4.5%) occurred in the open-circuit MFC (OC-MFC), where the generated FeS fine did not precipitate because of sulfide supersaturation. Enrichment of both sulfur-oxidizing bacteria (SOB), namely Helicobacteraceae in the anolyte and the electricity-producing bacteria, namely Desulfuromonadales on the anode likely accelerated the sulfur cycle through the biological and bioelectrochemical oxidation of sulfide in the anodic chamber, and effectively increased the molar ratio of total iron to sulfide, thus alleviating sulfide supersaturation in the closed circuitry. Enrichment of SOB in the anolyte might be attributed to the formation of FeS electricity wire and likely contributed to the stable high power generation. Bacteroidetes, Firmicutes, Proteobacteria, and Chloroflexi enriched in the anodic chamber were responsible for degrading complex organics in the FW. The treatment of real FW in the sulfur-cycle-mediated MFC also achieved high efficiency. This research provides a promising approach for the treatment of wastewater containing organic matters, heavy metals, and sulfate by using a sulfur-cycle-mediated MFC.

The rational fabrication of direct Z-scheme heterostructures photocatalysts is a pivotal strategy to boost the interfacial charge migration and separation. Herein, direct Z-scheme Bi2WO6/WO3 composites were rationally fabricated for the degradation of bisphenol A combined with the activation of peroxymonosulfate (PMS). The tight interface contact between Bi2WO6 and WO3 was successfully formed by the in situ epitaxial growth of ultrathin Bi2WO6 nanosheets at the surface of WO3 nanorods. The Bi2WO6/WO3 composite presented highly efficient catalytic performance toward degradation of BPA with PMS activation as compared to the WO3 and Bi2WO6. PMS can dramatically boost the photocatalytic activity of the composites. Moreover, the results of active radical scavenging experiments revealed that h+, &bull, O2&minus, and &bull, SO4&minus, are critical active species in the photodegradation reaction. Finally, the photocatalytic mechanism for the degradation of BPA is also discussed in detail. The great improvement of photocatalytic performance should be ascribed to the effective formation of the direct Z-scheme heterojunctions between Bi2WO6 and WO3, resulting in improved light absorption, an efficient transfer and separation of photoinduced charge carriers, and a considerable amount of the electrons and holes with strong reduction and oxidation abilities. The study might provide new inspirations to design and construct heterostructured nanomaterials with outstanding photoactivity for environmental remediation.

The flowback water (FW) from shale gas exploitation can be effectively treated by bioelectrochemical technology, but sulfide overproduction remains to be addressed. Herein, sulfate-reducing bacteria (SRB) meditated microbial fuel cells (MFCs) with anodic potential control were used. COD removal gradually increased to 67.4 ± 5.1% in electrode-potential-control (EPC) MFCs and 78.9 ± 2.4% in the MFC with open circuit (OC-MFC). However, in EPC MFCs sulfate removal stabilized at much lower levels (no more than 19.9 ± 1.9%) along with much lower sulfide concentrations, but in OC-MFC it increased and finally stabilized at 59.9 ± 0.1%. Partial sulfur reuse in EPC MFCs was indicated by the current production. Notably, thiosulfate was specially detected under low potentials and effectively oxidized in EPC MFCs, especially under -0.1 V vs. SHE, which probably related to the sulfur reuse. Metagenomics analysis showed that the anode with -0.1 and -0.2 V likely shunted electrons from cytochromes that used for reducing DsrC-S0 trisulfide and thus contributed to producing thiosulfate and decreasing sulfide production. Meanwhile, the anode with -0.1 V specially accumulated sulfur-oxidizing system (Sox) genes regarding thiosulfate and sulfite oxidation to sulfate, which concurred to the effective thiosulfate oxidation and also indicated the possible direct sulfite oxidation to sulfate during the sulfur cycling. But the anode of -0.2 V highly accumulated genes for thiosulfate and sulfite reduction. Both anodes also distinctly accumulated genes regarding thiosulfate oxidation to tetrathionate and sulfide oxidation to sulfur or polysulfide. Further, sulfur-oxidizing bacteria were specially enriched in EPC MFCs and likely contributed to thiosulfate and sulfite oxidation. Thus, we suggested that the higher electrode potential (e.g. -0.1 V) can shape a cryptic sulfur cycling, in which sulfate was first reduced to sulfite, and then reoxidized to sulfate by forming thiosulfate as an important intermediate or by direct sulfite oxidation. The results provide new sights on the bioelectrochemical treatment of wastewater containing complex organics and sulfate.

Highly dispersed Co nanoparticles with proper interaction with mesoporous support are benefit for the suppression of self-aggregation, which enhances its Fischer-Tropsch synthesis (FTs) activity. However, construct such Co based supported catalysts with high activity and stability in FTs by conventional mesoporous support, especially the common used mesoporous SiO2, has proven challenging due to their undesirable hydrothermal stability and poor reducibility. Herein, we developed a unique core@double-shell Co@SiO2@C structure with optimized interface of the mesoporous catalyst by introducing graphitic carbon layer which can weaken the interaction between metallic Co and silica. Transmission electron microscopy (TEM) images, together with Nitrogen adsorption-desorption characterization result, proved the well-defined core@double-shell structure of graphitic carbon modified catalyst. The Co@SiO2@C-2 material produced after optimizing the calcination temperature to 600°C process large surface area and pore volume, and show higher CO conversion (62.2%) and C5+ selectivity (62.2%) than Co3O4@SiO2 in a period of 100h. The significant improvement in the FTS performance of Co@SiO2@C is not only attributed to a good synergistic effect by a combination of the Co dispersion and reducibility. The unique core@double-shell structure with graphitic carbon modified interior pore-walls also contributes to the formation of heavy hydrocarbon, as well as the protecting with the metallic Co particles away from oxidation and aggregation.

Despite the toxicity of mercury for mammal has been widely studied in recent years, little is known on its impact on the soil microbiome. In this paper, the effects of mercury in soils microbial communities along a gradient of contamination from no to high concentration was assessed by the richness and diversity of microbial community using high throughput sequencing method. The richness of microbial community decreased gradually with the increase of culture time, while the low and medium concentration of mercury had little effect on the evenness of soil microbial community. Proteobacteria tolerated the mercury contamination, while Acidobacteria, Planctomycetes and Chloroflexi were sensitive to mercury pollution in phylum level. Omnitrophica and Ignavibacteriae microorganisms were very sensitive to mercury contamination and dead quickly when contaminated with mercury. Mercury contamination selected two mercury tolerance genuses which were Massilia and Burkholderia in genus level and at least 22 microorganisms such as Alkanindiges, Geothrix, Polycyclovorans and Sporichthya in genus which mainly from the Acidobacteria, Proteobacteria, Bacteroides, Chloroflexi and Omnitrophica phylum were sensitive to mercury. The bacteria tolerant to mercury in soil were Massilia and Burkholderia from Betaproteobacteria and Lysobacter, Luteimonas from Gammaproteobacteria, separately, they were Gram-negative bacteria with thin cell walls and complex ingredients that responded quickly to pollution stress.

Construction of heterojunction photocatalyst with excellent charge separation has attracted significant attention for solving the global energy crisis and environmental problems. Herein, a series of sandwich-structured BiOI/AgI/g-C3N4 composites were fabricated by a novel and facile method. The AgI was employed as a charge transmission bridge between BiOI and g-C3N4, which could result in more efficient charge transfer and better separation of charge carriers. The results indicated that the BiOI/AgI/g-C3N4 composites exhibited higher photocatalytic activity for the degradation of methyl orange (MO) and reduction of Cr(VI) than that of pure g-C3N4, BiOI, and BiOI/g-C3N4. The amount of AgI had a remarkable influence on the photocatalytic activity of the BiOI/AgI/g-C3N4 composites. Moreover, the BiOI/AgI/g-C3N4 composites exhibited high stability. Finally, a possible reaction mechanism on degradation of MO and reduction of Cr(VI) solutions over the composites was proposed. This work could facilitate a better understanding on the charge transfer process in the composite systems as well as provide a new approach to the rational design of novel advanced materials for practical photocatalytic application.

Incorporating plasmonic metal nanostructures into semiconductors has been regarded as an effective method to improve the photocatalytic activity for degradation of pollutants in water. In this study, a visible-light-driven photocatalyst Bi/Bi 2 WO 6 was successfully fabricated by a simple two-step route. The samples were systematically characterized by X-ray diffraction, Raman spectroscopy, infrared spectra, field-emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, UV–vis diffuse reflection spectroscopy, nitrogen absorption-desorption isotherms, and photoluminescence spectroscopy. The photocatalytic performance of the Bi/Bi 2 WO 6 composite was evaluated by the photocatalytic decomposition of Rhodamine B and 4-Chlorophenol under visible-light irradiation. The results revealed that the loaded Bi nanoparticles have great influences on the photocatalytic activity of Bi 2 WO 6 . The optimal Bi content for the photocatalytic activity of the Bi/Bi 2 WO 6 composite was determined. Moreover, the photocatalytic mechanism of the degradation processes was thoroughly elucidated. The enhanced photocatalytic performance of the Bi/Bi 2 WO 6 composite should be attributed to the strong visible light absorption, the surface plasmonic resonance (SPR) effect, the high migration efficiency of the electron-holes, and the interfacial interaction between Bi nanoparticles and Bi 2 WO 6 .

Novel Co@C core–shell nanoparticles were prepared by a straightforward low-temperature carbonization process. The industrially available lignin was used as a low-cost biorenewable carbon source for the first time. The products were characterized by X-ray diffraction, energy-dispersive X-ray spectrometry, transmission electron microscopy, nitrogen adsorption–desorption, and Raman spectrum. The results showed that the synthesized Co@C catalysts had a well-defined core–shell structure with a moderate degree of graphitization, and the metal Co nanoparticles with the sizes of 20–150 nm were wrapped by several layers of graphitic carbon. This unique core–shell structure is useful in a Fischer–Tropsch reaction since it can provide high adsorption space and the graphite carbon layer defects are beneficial for H2 dissociative adsorption. Furthermore, the shell of graphitic carbon layers could restrict the aggregation of the cobalt nanoparticles during the activation and reaction processes. Fischer–Tropsch synthesi...

H3PW12O40/TiO2–SiO2 was synthesized by impregnation method which significantly improved the catalytic activity under simulated natural light. The properties of the samples were characterized by Fourier transform infrared spectra (FTIR), X-ray powder diffraction pattern (XRD), Scanning electron micrographs (SEM), and Zeta potential. Degradation of methyl violet was used as a probe reaction to explore the influencing factors on the photodegradation reaction. The results show that the optimal conditions are as follows: initial concentration of methyl violet of 10 mg·L−1, pH of 3.0, catalyst dosage of 2.9 g·L−1, and light irradiation time of 2.5 h. Under these conditions, the degradation rate of methyl violet is 95.4 %. The reaction on photodegradation for methyl violet can be expressed as the first-order kinetic model, and the possible mechanism for the photocatalysis under simulated natural light is suggested. After used continuously for five times, the catalyst keeps the inherent photocatalytic activity for degradation of dyes. The photodegradation of methyl orange, methyl red, naphthol green B, and methylene blue was also tested, and the degradation rate of dyes can reach 81 %–100 %.

The g-C3N4 coated Ag/AgCl visible-light-driven photocatalysts were synthesized by a simple generic self-assembly approach at room temperature. The catalysts showed a uniform morphology with a controllable coating state on the scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images. The wide structure and surface characterization showed that the presence of g-C3N4 notably affected the surface properties of Ag/AgCl photocatalysts. The photocatalytic activity was significantly dependent upon the coating ratio of g-C3N4 under visible light, while 1 wt% was the best coating ratio. Recycling experiments confirmed that the g-C3N4–Ag/AgCl catalysts had superior cycle performance and stability. These results suggested that the self-assembly g-C3N4 coating treatment had critical influence on the visible-light-driven photocatalytic activity and stability of Ag/AgCl plasmonic photocatalyst. The enhanced photocatalytic activity and stability could be ascribed to the formation of steady g-C3N4–Ag/AgCl heterojunction, which results in the efficient space separation of photo-induced charge carriers.

Magnetic carbon nanocages (MCNCs) with multiform pore structure have been synthesized by a simple low temperature carbonization process. Biorenewable lignin was used as a cheap and carbon-rich precursor for the first time. The products were characterized by X-ray diffraction (XRD), nitrogen adsorption-desorption, energy dispersive X-ray spectroscopy (EDS), vibrating sample magnetometer (VSM), transmission electron microscopy (TEM), and Raman spectrum. XRD pattern and Raman spectrum showed that the product has a high degree of graphitization crystallinity. TEM micrograph indicated that the synthesized MCNCs have the hierarchical pore and cage structure. Due to these characteristics, the obtained magnetic carbon nanocages can be used as efficient and recycled adsorbents in the removal of dye staff from textile wastewater.

Highly-monodispersed g-C3N4/TiO2 hybrids with a core/shell structure were synthesized from a simple room temperature impregnation method, in which g-C3N4 was coated through self-assembly on the commercially available Degussa P25 TiO2 nanoparticles. Structural and surface characterizations showed that the presence of g-C3N4 notably affected the light absorption characteristics of TiO2. The g-C3N4/TiO2 heterojunctions with metal-free exposed surfaces were directly used as biocompatible photocatalysts for simulated jaundice phototherapy under low-power green-light irradiation. The photocatalytic activity and stability of g-C3N4/TiO2 were enhanced relative to pure P25 or g-C3N4, which could be ascribed to the effective Z-scheme separation of photo-induced charge carriers in g-C3N4/TiO2 heterojunction. The photoactivity was maximized in the 4 wt.% g-C3N4-coated P25, as the bilirubin removal rate under green light irradiation was more than 5-fold higher than that under the clinically-used blue light without any photocatalyst. This study approves the future applications of the photocatalyst-assisted bilirubin removal in jaundice treatment under moderate green light which is more tolerable by humans.

Highly dispersed Co nanoparticles with proper interaction with mesoporous support are benefit for the suppression of self-aggregation, which enhances its Fischer-Tropsch synthesis (FTs) activity. However, construct such Co based supported catalysts with high activity and stability in FTs by conventional mesoporous support, especially the common used mesoporous SiO

Highly-monodispersed g-C3N4/TiO2 hybrids with a core/shell structure were synthesized from a simple room temperature impregnation method, in which g-C3N4 was coated through self-assembly on the commercially available Degussa P25 TiO2 nanoparticles. Structural and surface characterizations showed that the presence of g-C3N4 notably affected the light absorption characteristics of TiO2. The g-C3N4/TiO2 heterojunctions with metal-free exposed surfaces were directly used as biocompatible photocatalysts for simulated jaundice phototherapy under low-power green-light irradiation. The photocatalytic activity and stability of g-C3N4/TiO2 were enhanced relative to pure P25 or g-C3N4, which could be ascribed to the effective Z-scheme separation of photo-induced charge carriers in g-C3N4/TiO2 heterojunction. The photoactivity was maximized in the 4 wt.% g-C3N4-coated P25, as the bilirubin removal rate under green light irradiation was more than 5-fold higher than that under the clinically-used blue light without any photocatalyst. This study approves the future applications of the photocatalyst-assisted bilirubin removal in jaundice treatment under moderate green light which is more tolerable by humans.

Graphitic carbon nanocages (GCNCs) with hierarchical pore structure have been synthesized by a simple low temperature carbonization process. Bio-renewable lignin was introduced as a low-cost and industrially available precursor for the first time. The products were characterized by X-ray diffraction (XRD), nitrogen adsorption–desorption isotherms, transmission electron microscopy (TEM) and Raman spectrum. XRD pattern and Raman spectrum showed that the product had a high degree of graphitization crystallinity. TEM indicated that the GCNCs have a hierarchical pore structure with graphitic frameworks. CO2 capture tests approved that the GCNCs exhibited a pretty elevated adsorption capacity (28.7 mg g−1), which can be attributed to the hollow nanocage structure and hierarchical porosity of lignin based GCNCs.

H4SiW6Mo6O40/SiO2was sensitized by H2O2solution that significantly improved its catalytic activity under simulated natural light. Degradation of basic fuchsin was used as a probe reaction to explore the influencing factors on the photodegradation reaction. The results showed that the optimal conditions were as follows: initial concentration of basic fuchsin 8 mg/L, pH 2.5, catalyst dosage 4 g/L, and light irradiation time 4 h. Under these conditions, the degradation rate of basic fuchsin is 98%. The reaction of photocatalysis for basic fuchsin can be expressed as the first-order kinetic model. After being used continuously for four times, the catalyst kept the inherent photocatalytic activity for degradation of dyes. The photodegradation of malachite green, methyl orange, methylene blue, and rhodamine B were also tested, and the degradation rate of dyes can reach 90%–98%.

The photocatalytic degradation of methyl violet using TiSiW12O40/TiO2as a novel eco-friendly catalyst under simulated natural light irradiation was investigated. The physical characterizations were carried out by TG/DTA, FT-IR, XRD, and UV-visible spectra. The effects of the initial methyl violet concentration, the solution pH, and catalyst dosage on the photocatalytic degradation rate of methyl violet were also examined. The results demonstrated that at optimal condition (initial concentration of methyl violet is 20 mg/L, catalyst dosage is 0.3 g, and the pH is 5.5), the degradation rate of methyl violet is as high as 82.4% after 3 h under simulated natural light irradiation. The reaction of photocatalysis for methyl violet can be expressed as first-order kinetic model.

In order to remove aquatic organic dye contaminants by utilizing the inexpensive and inexhaustible solar energy, the Keggin-type H3PW12O40was loaded on the surface of SiO2with the sol-gel method and sensitized by H2O2solution. The photocatalytic degradation of rhodamine B (RhB) by H3PW12O40/SiO2(x) under simulated natural light irradiation was investigated. The effects of the initial RhB concentration, the solution pH, and catalyst dosage on the photocatalytic degradation rate of RhB were also studied. The results demonstrated that at optimal condition (initial concentration of methyl orange is 10 mg/L, catalyst dosage is 0.8 g, and the pH is 2.5) the degradation rate of RhB is as high as 97.7% after 2 h under simulated natural light irradiation. The reaction of photocatalysis for RhB can be expressed as a first-order kinetic model.

TiO2 nanoparticles modified Bi2WO6 photocatalysts were prepared via a facile hydrothermal process. The photocatalytic activity of as-prepared TiO2/Bi2WO6 composites was investigated sufficiently by the photodegradation of rhodamine B (RhB), tetracycline hydrochloride (TC) and ciprofloxacin (CIP). The TiO2/Bi2WO6 composites, in which the molar ratio of TiO2 to Bi2WO6 is 1:1, exhibited optimum photocatalytic activity, which is found to increase by about 2.4 times more than that of pristine Bi2WO6 for the photodegradation of TC. The enhanced photocatalytic activity may be attributed to the higher surface area and the highly efficient charge separation between Bi2WO6 nanosheets and TiO2 nanoparticles. The mechanism of the photocatalysts is investigated by the determination of reactive species in the photocatalytic reactions, the photoluminescence measurement and photoelectrochemical analyses.

In this paper, H 3 PW 12 O 40 /MCM-48 was used as the photocatalyst for the degradation of methyl orange solution under light irradiation. It has been shown that the catalyst dosage, the initial concentration of methyl orange, irradiation intensity and irradiation time under light irradiation were the important factors of decolorizing. The best reaction conditions were: the concentration of methyl orange was 7 mg/ L, the dosage of H 3 PW 12 O 40 /MCM-48 was 6.0 g/L, irradiation time was 5.5 h. Under these conditions, the color removal could be up to 84.53 %.

In order to treat a mass of industrial wastewater nitrobenzene, a photocatalytic degradation method was studied in this paper. Phosphotungstic acid(H 3 PW 12 O 40 ) and titanium dioxide(TiO 2 ) were prepared, and a new-style catalyst H 3 PW 12 O 40 supported on TiO 2 (H 3 PW 12 O 40 /TiO 2 ) was prepared by the method of impregnation. We characterized them using X-Ray and FT-IR. The results proved that H 3 PW 12 O 40 possessed classical Keggin structure, TiO 2 was anatase and H 3 PW 12 O 40 can keep the Keggin structure on the TiO 2 . The effects of photocatalytic degradation of nitrobenzene wastewater under visible light in the presence of H 3 PW 12 O 40 /TiO 2 were investigated in detail. The research results revealed that reaction time, catalyst dosage, nitrobenzene original concentration were the main effects, and the biggest degradation of nitrobenzene wastewater was 94.1% at the optimum condition. The exhibited photocatalytic activity of the novel photocatalyst provided a promising solution for the degradation of nitrobenzene water contaminants.