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A plasmonic Au-TiO2/ZnO core–shell nanorod array (NR) photoanode exhibits efficient photoelectrochemical water splitting induced by the plasmonic energy and type II TiO2/ZnO heterojunction. The plasmonic Au-TiO2/ZnO core–shell NR photoanode provides a photocurrent density of 3.01 mA cm−2 at 1.7 V versus the reversible hydrogen electrode (RHE), almost 1.5 and 3 times higher than that of TiO2/ZnO core–shell NRs and TiO2 NRs upon exposure into simulated solar light. Moreover, the plasmonic Au-TiO2/ZnO core–shell NR photoanode shows a clear photocurrent density under visible-light irradiation (λ>400 nm) with a photocurrent density of 0.11 mA cm−2 at 1.23 V vs. RHE. The visible-light-excited photocurrent is mainly caused by the surface plasmon resonance effects produced by plasmonic Au nanoparticles, which benefit the visible-light absorption and charge separation of the wide-band-gap TiO2/ZnO heterojunction through the electrons and resonant energy transfer. Additionally, the strong interfacial interaction between TiO2 and ZnO leads to an effective photoinduced interfacial charge separation and transfer.

In this paper, vertically aligned one-dimensional (1D) TiO2@ZnO core-shell nanorods arrays (NRs) were prepared by a facile two-step hydrothermal method. The as-prepared TiO2@ZnO nanorods arrays were used as photoanode and exhibited high photoelectrochemical water splitting performance. A maximum photocurrent density of TiO2@ZnO nanorods arrays achieves to 2.02 mA cm−2 at 1.7 V vs. RHE, which is 2 times higher than that of pure TiO2 nanorods arrays. In addition, a significant cathodic shift in the onset potential and a stable photocurrent during 6000 s measurement are observed in TiO2@ZnO nanorods arrays. TiO2@ZnO core-shell NRs electrode shows a maximal conversion efficiency of 0.48% at 0.55 V vs. RHE, which is 2.7 times higher than that of the bare TiO2 NRs electrode. The improvement of photoelectrochemical properties can be attributed to the ingenious core-shell structure that enhances the interfacial interaction based on the type II heterojunction. An efficient interfacial charge separation and photoinduced charge transfer are achieved in 1D type-II TiO2@ZnO core-shell nanorods arrays.

In this paper, CuI, as a typical hole-transport channel, was used to construct a high-performance visible-light-driven CuI/BiOI heterostructure for photoelectrocatalytic applications. The heterostructure combines the broad visible absorption of BiOI and high hole mobility of CuI. Compared to pure BiOI, the CuI/BiOI heterostructure exhibited distinctly enhanced photoelectrocatalytic performance for the oxidation of methanol and organic pollutants under visible-light irradiation. The photogenerated electron-hole pairs of the excited BiOI can be separated efficiently through CuI, in which the CuI acts as a superior hole-transport channel to improve photoelectrocatalytic oxidization of methanol and organic pollutants. The outstanding photoelectrocatalytic activity shows that the p-type CuI works as a promising hole-transport channel to improve the photocatalytic performance of traditional semiconductors.

In this paper, ultrathin two dimensional (2D) g-C 3 N 4 nanosheet worked as support for the deposition of ultrasmall Pt nanoclusters. The average size of Pt nanocluster is about 3.2 nm. Firstly, the as-prepared Pt/g-C 3 N 4 modified electrode exhibited enhanced electrocatalytic ability in methanol oxidation reaction (MOR) compared to bare Pt nanoparticles. Moreover, when this electrode was upon visible light irradiation, higher performance of MOR was clearly observed compared to the traditional ambient electrocatalytic oxidation. This is owing to the synergistic effects of photocatalytic and electrocatalytic MOR together with the efficient interfacial charger transfer in Pt/g-C 3 N 4 . These results show that 2D ultrathin g-C 3 N 4 nanosheets can be used as promising photoactived support in the fields of solar and chemical energy conversion and also provide more insights into developing novel visible light photo-responsive electrode in direct methanol fuel cell.

Fuel cells, as a technology for the conversion of chemical energy into electrical energy, have been recognized as a promising sustainable power source. Traditional electrocatalysts, together with optically active semiconductors, have been selected as promising catalysts for the improvement of anodic reactions. Herein, cadmium sulfide (CdS) nanoclusters decorated on reduced graphene oxide (RGO) nanosheets were obtained by using a one-pot solvothermal method and then applied as photoactivated supports for the deposition of Pt nanoparticles. The ternary-composite-modified electrode displayed much higher catalytic properties for methanol oxidation than a binary Pt/CdS electrode. Interestingly, when the as-prepared Pt/CdS/RGO electrode was irradiated with visible light, both the catalytic activity and the stability were improved greatly. The synergistic effect of RGO nanosheets and photoirradiation promoted electrocatalytic performance and stability. Our results provide new insight into the development of highly efficient photoelectrocatalysts for applications in direct methanol fuel cells in the presence of visible-light illumination.

In this paper, a new and high-performance visible-light-activated electrode is designed in terms of two dimensional (2D) MoS2 nanosheets enwrapped 1D CdS nanowires as photo-activated support for depositing Pt nanoclusters. Compare to traditional ambient electrocatalytic process, the as-prepared photo-activated electrode shows evidently improved electrocatalytic activity and stability of methanol oxidation reaction (MOR) under visible light illumination. The efficient interfacial electron transfer from the excited CdS moieties to the decorated ultrathin MoS2 shell contributes to the synergistic effect of photocatalytic and electrocatalytic process for the boosting of catalytic efficiency.

In this paper, visible-light-driven photocatalysts composed of CdS nanoparticles, Nb2O5 nanorods (NbR) and N-doped graphene (NGR) nanosheets for photocatalytic water reduction to produce hydrogen have been synthesized. Under visible light irradiation, the prepared ternary nanocomposites showed distinctly enhanced photocatalytic performance for hydrogen evolution compared to bare CdS, NbR and CdS/Nb2O5. The sample with 2 wt.% NGR exhibited the highest photocatalytic activity, which is ca. 7.7 times as high as that evolved from CdS. The enhancement of photocatalytic performance may be related to the unique one dimension (1D) Nb2O5 structure with high surface-to-volume ratio, which can provide intimate interfacial contact between NbR and CdS nanoparticles, as well as the CdS/Nb2O5 heterojunction structure and two dimension (2D) NGR, which enhance the separation efficiency of photogenerated charge carriers. This work provides a promising and cost-effective method by combining the 0D CdS nanoparticles, 1D Nb2O5 nanorods and 2D N-doped graphene to form a ternary photocatalytic system for highly efficient hydrogen evolution from water without using any noble metals.

Efficient utilization of solar energy is a high-priority target and the search for suitable materials as photocatalysts that not only can harvest the broad wavelength of solar light, from UV to near-infrared (NIR) region, but also can achieve high and efficient solar-to-hydrogen conversion is one of the most challenging missions. Herein, using Au/La2Ti2O7 (BP-Au/LTO) sensitized with black phosphorus (BP), a broadband solar response photocatalyst was designed and used as efficient photocatalyst for H2 production. The optimum H2 production rates of BP-Au/LTO were about 0.74 and 0.30 mmol g−1 h−1 at wavelengths longer than 420 nm and 780 nm, respectively. The broad absorption of BP and plasmonic Au contribute to the enhanced photocatalytic activity in the visible and NIR light regions. Time-resolved diffuse reflectance spectroscopy revealed efficient interfacial electron transfer from excited BP and Au to LTO which is in accordance with the observed high photoactivities.

Graphite (Gr)-based composite materials have been attracting great interest from the scientific and engineering communities. While tremendous progress has been achieved in this field, it still remains a formidable challenge to hybridize pristine Gr with other components under ambient conditions without breaking the π-conjugated system of Gr. Herein, we report that Gr could be facilely hybridized with visible-light-driven plasmonic photocatalyst Ag/AgBr with the assistance of graphene oxide (GO) nanosheets under ambient conditions. We demonstrate that without the use of GO, Gr could not be well hybridized with Ag/AgBr, while a good hybrid Gr/GO/Ag/AgBr could be produced when GO nanosheets are introduced into the system. Our results show that compared to Ag/AgBr, GO/Ag/AgBr and Gr/Ag/AgBr species, thus-fabricated Gr/GO/Ag/AgBr hybrids could display substantially enhanced catalytic activity towards the photobleaching of methyl orange under visible-light irradiation. It is disclosed that the good hybridization between Gr and Ag/AgBr, which is mediated by GO, and the facilitated separation of photogenerated electrons and holes, which is promoted both by GO and Gr, contribute much to the boosted catalytic performances. Considering the excellent hybridization capability of GO, the exceptional electronic characteristics, versatile multifunctionality and low-cost of Gr, our protocol might be applicable not only to the Ag/AgBr-based plasmonic photocatalysts but also to a wide variety of other functional materials, wherein Gr/GO-based advanced materials of desired and reinforced functions or properties might be inaugurated.

Formation of surface heterojunctions in photocatalysts through tailoring the exposed crystal facets is an efficient strategy to boost charge separation. In this work, successive surface heterojunctions with large space-charge separation were achieved in a nanostep structured La2Ti2O7 (LTO NSP) single crystal exposed periodically with (010) and (012) facets. The three-dimensional (3D) nanosteps were found to enhance the photocatalytic hydrogen generation performance 35 and 74 times, compared with LTO nanosheets and nanoparticles with the same surface area, respectively. The ultrahigh superficial charge accumulation in LTO NSP verified by surface photovoltage (SPV) measurements suggested the efficient migration of photogenerated charge carriers to the surface. Femtosecond time-resolved diffuse reflectance (TDR) spectroscopy provided direct evidence that the electrons generated from the excited sites of LTO NSP were effectively delivered to the high energy (012) facets and temporarily stored there for further reduction reactions, originating from the successive (010) and (012) surface heterojunctions.

Reduction of soluble U(VI) to insoluble U(IV) oxide has been considered as an important approach to eliminate radioactive pollution and recycle uranium resource. The technology is hindered by the high cost, consumption of chemicals, and parallel generation of toxic wastes which are severe challenges today. In this paper, the photocatalytic reduction technology was utilized to eliminate UO22+ pollutant by constructing the highly efficient metal-free photocatalysts. Doping sulfur for substituting the lattice nitrogen of g-C3N4 (S-g-C3N4) modifies the electronic structure of g-C3N4 that displays the narrowed band-gap with the tuned conduction band and valence band levels as well as a good ability of electron-hole separation and carrier mobility. The photoreactivity of UO22+ reduction for S-g-C3N4 is 1.86 and 32 times of that for pristine g-C3N4 and N-TiO2 under visible light irradiation. The substitution of sulfur for lattice nitrogen was experimentally and theoretically identified as the cause of this unique electronic structure and, consequently, the excellent photoreactivity of S-g-C3N4 in the reduction of UO22+. The results may shed light on improving the reduction technology to eliminate U(VI) pollutant by doping strategies to design potentially efficient photocatalysts.

Structural Fe(III) is widely found in various coordination complexes and inorganic compounds. In this work, a typical Fe-based metal organic framework (MOF) (viz. MIL-100(Fe)) was chosen as an example in the activation of peroxydisulfate (PDS) for the removal of antibiotic pollutants. Interestingly, an auto-acceleration effect was observed in the process of MIL-100(Fe) activating PDS aided by visible light irradiation. Compared to the processes with MIL-100(Fe)-activated PDS alone and the photo-activated PDS alone, the degradation efficiency of sulfamethoxazole (SMX) obtained in the visible light assisted PDS activation by MIL-100(Fe) process was enhanced by 2.1 and 5.6 times, respectively. Therein, the photogenerated electrons from MIL-100(Fe) carried out an in situ reduction of the surface structural Fe(III) to form Fe(II), which in turn significantly improved the PDS activation efficiency in the generation of ·OH and O2-· radicals for the removal of SMX. The degradation pathways of SMX were deduced based on the experimental results and theoretical calculations. Acute toxicity estimation indicated the formation of less toxic products after the treatment of SMX. Additionally, degradation of five antibiotics in the real wastewater were investigated to further confirm the advantages of such in situ photoreduced structural Fe(III) in MOFs to activate the PDS process.

The search for a suitable heterogeneous catalyst in peroxymonosulfate (PMS) activation holds tremendous promise for the degradation of organic pollutants. Two-dimensional (2D) transition metal dichalcogenides such as WS

The combination of different semiconductors to form a heterojunction plays an important role for exploring new visible-light-driven electrocatalysts. Herein, a two-dimensional (2D) Bi2WO6/La2Ti2O7 (LTO) heterojunction has been synthesized and to be as carrier of Pt nanoparticles. Subsequently, electrocatalytic activity and stability of the as-obtained Pt-Bi2WO6/LTO has been evaluated in methanol oxidation reaction (MOR) under the action of visible light and electricity. Results indicate that Pt-Bi2WO6/LTO sample displays excellent catalytic performance and stability with assistance from visible light. Under identical conditions, the current intensity of MOR on the Pt-Bi2WO6/LTO modified electrode is found to reach 1409 mA mg−1Pt, which is 3.92 times higher than the measured Pt-Bi2WO6 modified electrode (359.8 mA mg−1Pt). In addition, the current density of MOR on Pt-Bi2WO6/LTO electrode decreases by 2.85% after scanning for 300 cycles. Furthermore, Pt-Bi2WO6/LTO is 6.99 times more resistant to poisoning than the Pt-Bi2WO6 electrode determines by chronopotentiometry under visible light illumination. The presented results indicate that a Pt-Bi2WO6/LTO nanocomposite is a viable alternative photo-electric catalyst, providing a potential new basis for the future development of catalysts in fuel cell reactions.

Two dimensional polymers have emerged in recent years as useful materials for the development of catalysts for future energy demand. However, the synthesis of ultrathin organic two dimensional polymers is still limited and further development is necessary. Here we present the synthesis of nanometer-thick two-dimensional (2D) porphyrin polymer nanodisks via the exfoliation of covalent organic frameworks, and evaluate their performance in the hydrogen evolution reaction under irradiation with broadband light. The nanodisks are synthesized through the simultaneous axial coordination of pyridines and metal ions to produce 2D porphyrin nanodisks of 1 nm average thickness. Importantly, the polymer composite with platinum-reduced graphene oxide exhibits hydrogen evolution activity upon irradiation with visible and NIR light. These results represent the use of 2D ultrathin polymer nanodisks derived from covalent organic frameworks in heterogeneous photocatalytic processes. The exfoliation of covalent organic frameworks is a potential route to interesting two-dimensional materials. Here, the authors report a strategy incorporating metal ions and axial ligands to facilitate exfoliation of porphyrin COFs, and examine the photocatalytic activity of the resulting nanomaterials.

The recent increase in the use of alternative flame retardants (FRs) in consumer products has led to emerging contaminants in the environment. Identification of novel FRs is urgently needed because the potential threat posed by these chemicals has provoked considerable attention, but the details of the threat are not yet widely understood. In this study, two novel triazine-based FRs, tris(2,3-dibromopropyl) isocyanurate (TDBP-TAZTO) and 2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine (TTBP-TAZ), were identified in dust samples from an e-waste recycling area in China. Two legacy FRs, namely, tetrabromobisphenol A (TBBPA) and hexabromocyclododecane (HBCDD), were also analyzed for comparison. The mean level of TDBP-TAZTO in the e-waste dust samples was found to be much higher (2060 ng g−1) than that of HBCDD (526 ng g−1), while the mean level of TTBP-TAZ in residential dust samples was moderately higher (119 ng g−1) than that of HBCDD (35.7 ng g−1). A comparison of the TDBP-TAZTO and TTBP-TAZ concentrations with those of other alternative and legacy FRs indicated that TDBP-TAZTO is a major FR that is currently used in China. The estimated daily intake of TDBP-TAZTO via dust ingestion for occupational workers was much higher than that of HBCDD and was also much higher than for local adults and children. Exposure to TDBP-TAZTO poses a potentially high risk to the health of the local population, especially for the occupational workers, when the multicomponent chemical ‘cocktail’ effects are taken into account. More investigations on the environmental behaviors and risk factors of TDBP-TAZTO and TTBP-TAZ in various environmental matrices, as well as their toxicological effects, should be performed in the future.

Antibiotics as emerging pharmaceutical pollutants have seriously not only threatened human life and animal health security, but also caused environmental pollution. It has drawn enormous attention and research interests in the study of antibiotics removal from aqueous environments. Graphene, an interesting one-atom-thick, 2D single-layer carbon sheet with sp2 hybridized carbon atoms, has become an important agent for removal of antibiotic, owing to its unique physiochemical properties. Recently, a variety of graphene-based nanomaterials (GNMs) are reported to efficiently remove antibiotics from aqueous solutions by different technologies. In this review, we summarize different structure and properties of GNMs for the removal of antibiotics by adsorption. Meanwhile, advanced oxidation processes (AOPs), such as photocatalysis, Fenton process, ozonation, sulfate radical and combined AOPs by the aid of GNMs are summarized. Finally, the opportunities and challenges on the future scope of GNMs for removal of antibiotics from aqueous environments are proposed.

To evaluate the feasibility of high-resolution magnetic resonance imaging (MRI) with a simultaneous non-contrast angiography and intraplaque haemorrhage (SNAP) sequence in identifying cervical artery dissections (CeAD).Fifty-three patients with suspected CeAD underwent the SNAP sequence (including non-contrast magnetic resonance angiography [MRA] and heavy T1-weighting vessel wall images simultaneously in a single scan) and conventional MRI sequences (including three-dimensional [3D] time-of-flight MRA and T1-weighted black-blood imaging [T1W BB]) and cervical vascular ultrasound (CVUS). In diagnosis of CeAD, the diagnostic sensitivity and specificity of SNAP, and the diagnostic coherence between SNAP and conventional sequences and between SNAP and CVUS was analysed. At follow-up, the absolute signal (AS) and signal index (SI) of the intramural haematoma (IMH) between vessel wall images on SNAP and T1W-BB images were compared. The image quality of SNAP was analysed by comparing the signal-to-noise ratio (SNR) between vessel wall images from the SNAP and T1W-BB sequences.The SNAP sequence was found to provide good performance in the diagnosis of CeAD (sensitivity 72.2%, specificity 98.2%); good agreement was found between SNAP and conventional sequences (Cohen's κ=0.76, p0.05); and excellent agreement was found between SNAP and CVUS (Cohen's κ=0.83, p0.05). There was no significant difference between AS or SI of the IMH of the vessel wall images within the SNAP and T1W-BB sequences during the review. The SNAP sequence had higher SNR of the IMH compared to T1W-BB, T2W-BB, proton-density-weighted volume isotropic turbo-spin-echo acquisition imaging (PD-VISTA) sequences (p0.05).The SNAP sequence holds the potential to be preferred choice for screening of patients with a high suspicion of CeAD and for the follow-up of IMH after treatment.

In this paper, a two-dimensional (2D) hybrid material of molybdenum disulfide (MoS2)/reduced graphene oxide (RGO) is facilely synthesized and used as an ideal support for the deposition of Pt nanoparticles. The as-prepared Pt/MoS2/RGO composites are further worked as electrocatalysts towards ethylene glycol oxidation reaction (EGOR). In addition, when alloying with Ni, the composite shows obvious enhancement in electrocatalytic performance for EGOR. Specifically, the optimized molar ratio of Pt to Ni is 3:1, namely Pt3Ni/MoS2/RGO performs the strongest current density of 2062 mA mg−1Pt, which is 11.1, 5.80 and 2.40 times higher than those of Pt, Pt3Ni and Pt/MoS2/RGO electrodes, respectively. The systematically electrochemical measurements indicate that the largely promoted electrocatalytic performances of Pt3Ni/MoS2/RGO are mainly attributed to the synergistic effect of Ni and Pt, and 2D sheets of MoS2/RGO. This excellent performance indicates that the reported electrocatalytic material could be an efficient catalyst for the application in direct ethylene glycol fuel cell and beyond.

The effects of RE content and cold rolling and annealing on the microstructure and corrosion resistance of Al-Mn-RE alloy were studied by means of metallographic microscope, scanning electron microscope and electrochemical workstation. The results show that the eutectic phases with different sizes and irregular shapes can be seen in Al-Mn-xRE alloys. With the addition of different RE content, the amount of eutectic silicon increases, the long strip eutectic structure fines and gradually turns into spherical or short rod-like structure. When RE content reaches 0.25% or more, the eutectic structure begins to coarsen. With the increase of RE content, the corrosion potential and pore size of Al-Mn-xRE alloys increase. The corrosion potential of Al-Mn-0.18RE alloy shows a trend of positive and negative migration first, and the corrosion current density decreases first and then increases, the maximum corrosion resistance is obtained when the RE content is 0.18%. The order of corrosion potential and pitting corrosion potential of Al-Mn-0.18RE alloy from high to low is: homogenized state> cold rolled + 325 °C annealed state> rolled state> cold rolled + 475 °C annealed state. The corrosion resistance of the Al-Mn-0.18RE alloy after rolling is lower than that of the homogenized state, but the subsequent stabilization annealing treatment at 325°C can improve the corrosion resistance.

Construction of step-scheme (S-scheme) heterojunction with superior redox ability is emerging to be an efficient way to develop high-efficiency photocatalysts for environmental pollution control. Herein, a new S-scheme heterojunction photocatalyst built from BiOCl with oxygen vacancies and CuBi2O4 was developed. Compared to pristine CuBi2O4 and BiOCl, this S-scheme heterojunction photocatalysts (BOC/CBO) show enhanced photocatalytic performance in removing aqueous diclofenac (DCF) and gaseous nitric oxide (NO) under visible light irradiation, which is mainly ascribed to the improved charge separation and transfer and redox ability by the S-scheme heterojunction structure and the enhanced catalytic oxidation by tunning the coordination structure and electronic states of O2 by oxygen vacancies. Further, the detailed DCF degradation pathways were studied and confirmed by high performance liquid chromatography–mass spectrometer (HPLC–MS). At last, a possible photocatalytic reaction mechanism based on such a S-scheme heterojunction (BOC/CBO) is proposed. This study provides an insight in constructing high-performance S-scheme heterojunction photocatalysts for environmental pollution remediation.

Advanced oxidation processes (AOPs) based on heterogeneous catalytic activated peroxymonosulfate (PMS) have been becoming alternatives to conventional wastewater treatment technologies to directly degrade chemical contaminants. To build dual/multi redox cycles of different metal ions may be an effective means for better PMS activation. Herein, this study designed Mn3O4/CuBi2O4 with dual redox cycles of Mn(III)/Mn(IV) and Cu(I)/Cu(II) to activate PMS for efficiently decomposing and mineralizing diclofenac sodium (DCF). Under optimal reaction conditions, DCF (50 mg/L) was degraded totally within 10 min, and TOC removal rate reached up to 74.3%. The possible mechanism of PMS activation by Mn3O4/CuBi2O4 was proposed, wherein dual redox cycles of Mn(III)/Mn(IV) and Cu(I)/Cu(II) on Mn3O4/CuBi2O4 effectively facilitated PMS activation to generate ·O2−, 1O2, SO4·− and ·OH, which was responsible for DCF degradation. Moreover, combined with degraded products detected by high resolution liquid chromatography coupled to mass spectrometry and corresponding toxic assessment results, the possible degradation pathways of DCF were proposed and the relative toxicity of degraded products was evaluated. This work may be useful for developing stronger heterogeneous activators of PMS to construct more efficient AOPs for purifying wastewater.

The major challenge of Fenton and Fenton-like technologies is promoting the effective transformation of Fe3+ to Fe2+. Photoinduced ligand-to-metal charge transfer (LMCT) enables charge to transfer effectively from the complex ligand to metal ions for the subsequent redox reactions. This study shows that photoactivated LMCTs relying on internal charge transfers occurred from the pollutant complex to the Fe3+ center and followed the in situ transformation of Fe3+ to Fe2+ without the addition of other ligands or agents. Using the antibiotic pollutant sulfamethoxazole (SMX), a direct Fe-SMX complex is formed and enables visible light to be used to activate peroxydisulfate (PDS) by Fe3+ for the rapid degradation of SMX at a rate 6.5-times higher than that observed by the conventional Fe2+/PDS system. This study outlines a new and cost-effective LMCT activation approach and broadens our knowledge of the ability of Fe3+ to be applied in Fenton-like reactions for environmental remediation.

The wide use and distribution of sulpiride (SP) has caused potential threats to the water environment and human health. In this study, ultrathin S-doped graphitic carbon nitride nanosheets (US-CN) was successfully synthesized and characterized, and its SP removal efficiency was evaluated under various conditions via the visible-light-assisted peroxydisulfate (PDS) activation method. The degradation pathways and mechanism were also discussed through quenching experiments, density functional theory (DFT) calculations, and intermediate products detection. After sulfur doping and ultrasonic treatment, graphitic carbon nitride (CN) possessed an ultra-thin and porous structure, which facilitated the electronic distribution and more photocurrent, thus resulting in the excellent stability and removal efficiency for SP via PDS activation upon visible light irradiation. The singlet oxygen (1O2) generated by the US-CN/PDS/VL system played a significant role in SP degradation. Based on the bonds of electron-rich atoms fracturing and the SO2 extrusion, the SP degradation pathway was proposed. This work provides a useful information for the SP photocatalytic degradation via PDS activation.

Photoelectrochemical (PEC) process has been demonstrated to exert enormous potential in the fields of analysis, and the rational design of PEC sensors are vital for the practical applications. In this study, the g-C3N4/Ti3C2 composite was proposed as a photoelectrochemical sensing material for the detection of ciprofloxacin (CFX). Characterization methods proved the formation of g-C3N4/Ti3C2 compounds and their superior optoelectronic performance. Moreover, the measurement of PEC properties exhibited that the introduction of Ti3C2 and visible light would improve the electron migration efficiency and the separation of photogenerated electron-hole pairs, thereby displaying the synergistic effect to promote the photoelectric performance. More importantly, the current density of g-C3N4/Ti3C2 was linearly proportional to the concentration of CFX ranging from 0.4 to 1000 nM, and the detection limit (3S/N) was 0.13 nM. In addition, such a PEC sensor demonstrated long-term stability, good reproducibility and selectivity. Finally, the real commercial sample detection was measured to confirm the possibility of practical applications. Thus, the g-C3N4/Ti3C2 photo-electrocatalyst provides a new method for CFX detection with high selectivity and sensitivity.

The advantage of light-to-heat conversion can be employed as an optical alternative for environmental remediation. As a proof of concept, for the first time we introduce the light-to-heat conversion application in peroxydisulfate (PDS) activation by molybdenum disulphide (MoS2) under near infrared (NIR) light irradiation. Theoretical kinetics analysis suggests that the reaction rates of PDS activation is increased up to 9.2 times when increasing from room temperature to 50 °C. MoS2 has the capability to quickly convert NIR light to heat energy (~45°C), thereby being able to activate PDS to generate hydroxyl and sulfate radicals. The observed reaction rate of carbamazepine degradation by NIR/MoS2/PDS process is 6.5 times of that in MoS2/PDS and even 2.6 times higher than the sum of those in NIR/MoS2, MoS2/PDS and NIR/PDS processes. Combining with theoretical calculation and oxidation species analysis, a new photo-activation PDS mechanism is proposed, in which MoS2 absorbs the energy of light to generate heat energy for overcoming the energy barrier of PDS activation. By loading MoS2 on carbon cloths, a flexible photothermal membrane is designed for practical application of sunlight-to-heat conversion to activate PDS with high efficiency, stability, and recycling. The present results demonstrate the potential of applying light-to-heat conversion in Fenton-like processes in pollution control, which opens new avenues towards utilization of inexhaustible solar energy and novel approaches for environmental remediation.

The contamination of antibiotics micro-pollutants in water bodies causes increasing concerns currently. Semiconductor-based photocatalysis has been considered as an efficient method for the removal of contaminations from aquatic environment, while its catalytic performance always depends on facets in semiconductor. To deeply understand the relation between facet and catalytic process, herein we take the different morphologies of Ag3PO4 as the cases to investigate the charge‐carrier dynamics in different facets of Ag3PO4 for the photodegradation of antibiotic ciprofloxacin (CIP), sulfamethoxazole (SMX), and tetracycline (TC). The degradation results show that Ag3PO4 tetrahedrons with dominated {111} facets exhibit 1.83 times higher CIP degradation rate than Ag3PO4 cubes with dominated {100} facets. Femtosecond time-resolved diffuse reflectance (fs-TDR) spectroscopy is used to give the detail charge-carrier dynamics in different facets of Ag3PO4 in accordance with the antibiotics pollutants degradation rate, which provides a more direct and visual proof.

Advanced oxidation processes involving the visible-light-assisted peroxymonosulfate (PMS) are emerging as promising approaches for treating antibiotic pollutants. Here, Fe(II)/V(IV) self-doped FeVO4 nanobelts were synthesized and employed to build a visible-light-assisted PMS activation system for degrading antibiotic sulfamethoxazole (SMX). Compared with PMS/FeVO4, PMS/Visible light (VL), or PMS system, the PMS/FeVO4/VL system showed 3.9, 14.0, or 14.1 times improved for the removal of SMX, respectively. The reason behind this is the organic combination of the VL photocatalysis and transformation of Fe(II)/V(IV) to Fe(III)/V(V) over FeVO4, namely when photocatalytic behavior over FeVO4 can produce electrons (e-) and holes (h+) to activate PMS or directly degrade SMX, the transformation of Fe(II)/V(IV) to Fe(III)/V(V) will also happen to donate some e- for PMS activation simultaneously. Such a system can also effectively remove SMX from actual water bodies such as medicine wastewater, river water, tap water, and rainwater. This work not only provides an effective system for treating SMX polluted wastewater, but also gives some new insights to understanding the mechanism involving Fe-based binary metal oxide activating peroxymonosulfate.

A heterojunction of a perovskite-type La2 Ti2 O7 (LTO)/CdS quantum dot (QD) nanocomposite was prepared by the chemical bath deposition method. The solar-light-driven H2 generation results show that this CdS QDs/LTO heterojunction exhibits great improvement in the photocatalytic H2 production and its photoelectrochemical properties in comparison with pure CdS QDs and LTO nanosheets. A possible enhanced mechanism of photoinduced interfacial charge transfer between CdS and LTO is proposed for the heterojunction. The shift of the CdS conduction band (CB) edge can enlarge the CB potential difference between CdS QDs and LTO, enhancing transferred driven force of the interfacial electrons and finally improving the two components' separation activity of photogenerated carriers. This study provides a promising method for constructing an efficient photoinduced interfacial charge transfer over LTO and CdS QD heterojunctions for photocatalytic hydrogen production.

A new hybrid silicon-phthalocyanine phenyl covalently functionalized graphene (SiPc(phenyl)2G2) was synthesized. The high fluorescence quenching efficiency and enhanced photocurrent suggested a rapid photoinduced energy transfer from SiPc(phenyl) moiety to graphene sheets through the covalent bond. Using the above synthesized hybrid as a photosensitizer, the SiPc(phenyl)2G2 functionalized Pt nanocomposite (SiPc(phenyl)2G2/Pt) was easily obtained via photodeposition method. The as-prepared SiPc(phenyl)2G2/Pt showed efficient photocatalytic hydrogen generation from water splitting under both UV–vis and visible light irradiation. Interestingly, with the aid of surfactants, the photocatalytic activity and stability of the SiPc(phenyl)2G2/Pt nanocomposites in the solution were distinctly improved owning to the nanocomposite aggregation prevention. This investigation demonstrates a unique approach to construct stable high photoresponisve organic hybrid composites for solar energy utilization.

By doping Cu(I) ions in Zn0.3Cd0.7S, a novel p-type Cu doped Zn0.3Cd0.7S modified graphene (Zn0.3Cd0.7S (Cu)/GR) film photocathode was prepared. The as-prepared p-type Zn0.3Cd0.7S (Cu)/GR photocathode and an n-type WO3/graphene (WO3/GR) photoanode were used to assemble a photoelectrochemical tandem cell. Through examination of the optoelectronic and photoelectrochemical properties of Zn0.3Cd0.7S (Cu)/GR and WO3/GR photoelectrode, we evaluate the feasibility of the tandem cell for overall water splitting under UV–vis light irradiation. The optimal Cu doping in Zn0.3Cd0.7S photocathode concentration was found to be 6%. The rates of hydrogen and oxygen evolved from this tandem cell with the optimal electrodes were 65.6 and 12.3 μmol g–1 h–1 (80.5 and 15.1 μmol cm–2 h–1), respectively. This study suggests a promising method for constructing an efficient photoelectrochemical tandem device for overall water splitting.

A cadmium sulfide quantum dots sensitized Pt (Pt-CdS) composite was synthesized using a solvothermal method and characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-vis diffuse reflectance spectroscopy. The catalytic properties of the as-prepared electrode for methanol oxidation were evaluated by cyclic voltammetry (CV), chronoamperometry, electrochemical impedance spectrum (EIS) and photocurrent responses. The as-prepared Pt-CdS electrode displayed a significant enhancement in the electrocatalytic activity and stability for methanol oxidation in the presence of visible light irradiation. The synergistic effect of both the electro- and photocatalytic reaction contributes to this enhanced catalytic performance. Our result suggests a new paradigm to construct photoelectrocatalysts with high performance and good stability for direct methanol fuel cells with the assistance of visible-light illumination.

Artificial photocatalytic conversion of CO2 into value-added and renewable fuels has been recognized as a promising approach for solving environmental problems and energy crisis. Achieving this goal, developing a photocatalyst to simultaneously manifest high efficiency, selectivity, and durability is urgent need. Herein, one of all-inorganic cesium lead halide perovskite (viz. Cs4PbBr6) with hole-in-microdisk structure hybridized with reduced graphene oxide (rGO) is reported as an effective photocatalyst for reducing of CO2. Our results show that Cs4PbBr6/rGO exhibited high efficiency, selectivity, and durability of CO2 reduction capacity to CO, catalyzing at a rate of 11.4 μmol g-1h-1 with a maintaining stability of 60 h. Residual oxygen impurities as defects in the rGO sheets are demonstrated for facilitating CO2 activation and reduction capacity to CO. This finding provides a facile pathway for designing high performance perovskite photocatalyst with high selectivity and durability with the aid of defects engineering.

The interface defects caused by lattice mismatch between semiconductors and the homogeneous doping of dopants in host semiconductors without layered structure are the challenges in the construction of high performance photocatalysts. Herein, a smart template induced in-situ growth method is developed to synthesize a quantum dot level Cu&In co-doped CdS (CuIn-CdS) hetero-phase junction with multi-arm nanorod morphology for the first time. Due to the in-situ growth of CdS induced by Cu-doped In2S3 nanorods, the homogeneous doping of Cu and In in CdS is easily realized, which efficiently expands the light absorption ability of CdS. Moreover, owing to the hetero-phase junction formed between hexagonal and cubic CdS rather than heterostructure, the lattice mismatch and the interface defects are greatly minimized, which effectively facilitates the separation and transfer of photogenerated charge carriers. As a result, the optimal CuIn-CdS exhibits a photocatalytic H2 evolution rate of 105.44 mmol/g/h (corresponding to the apparent quantum efficiency (AQE) of 32.72% at 400 nm), which is about 55.0, 10.9 and 9.7 times higher than that of pristine CdS, Cu-CdS and In-CdS, respectively. This work provides a new way to overcome interface defects and realize homogeneous doping at the same time for exploring new photocatalysts with high performance.

Direct conversion CO2 to useful chemical fuels by photocatalysis has been considered to be a promising strategy for renewable energy production. The realization of this goal relies mainly on the development of photocatalysts with ideal charge separation efficiency. Here, we use all-inorganic perovskite nanocrystals (CsPbBr3) immobilized on two-dimensional (2D) black phosphorus nanosheets (BP), resulting in a new and effective CsPbBr3/BP photocatalyst for CO2 photoreduction. Compare to pristine CsPbBr3, the introduction of BP generates more active sites for facilitating CO2 activation and trapped the excited electrons from CsPbBr3 with high charge separation efficiency. Time-resolved photoluminescence and transient absorption measurements together with density functional theory calculations provide a clear elucidation of the charge separation pathways that contribute to the enhanced CO2 conversion rate. This significant feature provides a new venue for constructing all-inorganic perovskite-based photocatalyst by combining with BP for solar energy conversion and artificial photosynthesis.

In this paper, a two dimensional/two dimensional (2D/2D) heterostructure of Ti3C2/g-C3N4 (T/CN) was constructed and used to activate peroxymonosulfate (PMS) for the degradation of diclofenac (DCF) in water in the presence of light illumination. Compared with single photocatalytic process by T/CN (0.040/min) and with pure g-C3N4 nanosheets in PMS system (0.071/min), 5.0 and 3.0 times enhanced activities were achieved in the T/CN-PMS system at optimum Ti3C2 (1.0 wt%) loading under light illumination (0.21/min). Moreover, the decomposing processes of DCF in T/CN-PMS system were applicable in a wide initial pH range (3∼14), therefore, overcoming the limitation of pH dependence in traditional PMS system. Based on the synergistic effect of photocatalysis and PMS oxidation processes, the 1O2 was generated as primary reactive species for the removal of DCF in T/CN-PMS system. The DCF degradation mechanism was further proposed through the results of liquid chromatography-mass spectrometry (LC-MS) and density functional theory (DFT) calculations.

The widespread use of pharmaceuticals and personal care products (PPCPs) is posing serious environmental issues, and it is imperative to develop an effective treatment for removing PPCPs. Herein, we used a binary metal oxide of dibismuth copper oxide (CuBi2O4) to activate peroxymonosulfate (PMS) for removing PPCPs. Interestingly, above system was evidently improved by introducing visible light. Photocatalysis and the synchronous transformations of Bi3+/Bi5+ and Cu2+/Cu+ valence states over CuBi2O4 are combined organically. Such a synergistic effect promotes the production of more active species (e.g., 1O2, h+, OH, SO4 −) for further resulting in the rapid degradation of PPCPs. Taking tetracycline (TC) degradation as a model, the detailed degradation pathways of TC and the toxicity of degraded products were identified. This work not only provides a facile yet effective catalytic reaction system for removing PPCPs, but also gives some further insights to understand the reaction mechanism involving Bi-based or other like binary metal oxidative materials.

Here, we are reporting a new visible-light-driven composite photocatalyst Ti3C2-Bi/BiOCl which builts from Ti3C2 nanosheets and Bi/BiOCl microspheres. It exhibits a higher photocatalytic performance than BiOCl and Bi/BiOCl in degrading antibiotic ciprofloxacin (CIP) under visible light illumination. Such an improved activity for Ti3C2-Bi/BiOCl can be attributed to the introduction of Ti3C2 and Bi. The Bi and Ti3C2 not only significantly broaden the light adsorption of Bi/BiOCl in visible-light region, but also can be served as an excellent “electron trap” for boosting the separation and transfer of photogenerated electrons/holes in Ti3C2-Bi/BiOCl because of its favorable electrical conductivity. Moreover, Ti3C2-Bi/BiOCl shows an well reusability in the five cycles of CIP degradation. This work not only provides a new efficient heterojunction photocatalyst for pollutant abatement in water, but also gives some further insights in constructing multi-component photocatalysts that can work under visible light.

Photo-assisted electrocatalysis based on noble metal/semiconductor electrode has attracted great interest recently. In this paper, a new two dimensional 2D/3D heterostructure of Bi2WO6 nanosheet/Cu2S snowflake was facile synthesized firstly and then employed as a support for the depositing of Pt nanoparticles. The as-synthesized Pt-Bi2WO6/Cu2S composite was further used as working electrode in the application of electrocatalytic methanol oxidation reaction (MOR). The electrocatalytic performances were evaluated by cyclic voltammetry, CO stripping voltammetry, chronoamperometry, chronopotentiometry, photocurrent response, electrochemical impedance spectra and photo&electrocatalytic organic pollutants degradation. It is noted that the introduction of Cu2S improved electrocatalytic activity and stability of Pt-Bi2WO6 for MOR under visible light illumination. The introduced 3D snowflake like Cu2S not only provides more activate sites for depositing Pt nanoparticles and trapping the reactivated molecules, but also acts as a hole transport channel, which can effectively separate the photogenerated electron-hole pairs excited by Bi2WO6, thereby improving the photo-assisted electrocatalytic performance. The present results provide a desirable noble metal electrocatalyst support by using 2D/3D heterojunction in the application of traditional electrocatalytic reactions.

The synthesis of thin-layered two dimensional (2D) organic nanomaterials has recently attracted considerable attention because of their potential for use in photo-electrochemistry and photocatalysis. To synthesize thin-layered organic polymers such as polymer nanosheets and nanodisks, covalent organic frameworks (COFs) with benzene or triphenylbenzene core units, are immersed or mechanically sonicated in common solvent. However, it is still challenging to exfoliate the π-conjugated COFs containing such porphyrin units. In this study, we investigated the liquid-phase exfoliation of COFs comprising porphyrin using common solvents, and found that tuning the solvent surface energy as well as mechanical stirring is crucial for effective exfoliation. We synthesized thin-layered, covalent organic porphyrin nanodisks in a common solvent by mechanical stirring and observed their enhanced photocatalytic activity.

The search for a suitable heterogeneous catalyst in peroxymonosulfate (PMS) activation holds tremendous promise for the degradation of organic pollutants. Two-dimensional (2D) transition metal dichalcogenides such as WS2 exhibit broad applications in heterogeneous catalysis, and we first extended its application in PMS activation in this work. It was found that WS2 could efficiently activate PMS resulting in the degradation of diclofenac (DCF). The results show that the PMS offers direct oxidation, and WS2 could initiate PMS to produce singlet oxygen (1O2) and superoxide radical (·O2−). This resulted in the improved removal of DCF in the WS2/PMS system. Furthermore, the degradation pathway of DCF was proposed according to the detected intermediates/products and density functional theory (DFT) calculation. Degradation intermediates and the evaluation of product toxicity indicated that the developed WS2/PMS system was a safe and detoxifying process while also offering efficient DCF removal. This study offers more insight into the development of suitable materials for the activation of PMS and gives clear direction for the degradation of DCF and its toxic intermediates.

The large consumption and discharge of sulfonamides (SAs) have potentially induced antibiotic resistance genes, posing inestimable threats to humans and ecosystems. In the present study, five SAs with different substituents were regarded as target compounds to be degraded using the nonradical dominated peroxydisulfate (PDS) activation process by the combination of 1O2 oxidation and direct electron transfer. The degradation rates, toxicities and pathways of SAs largely varied with their substituents. For instance, sulfathiazole with five-membered substituent had the highest degradation rate of 0.19 min-1, which was 3.8 times as the rate of sulfanilamide (0.05 min-1) without substituent. Then the theoretical calculation was adopted to further confirm that different substituents on the SAs could influence the molecular orbital distribution and their stability, thus resulting in the different removal rate of SAs. Finally, the products of different SAs were concisely deduced to take insight into the effects of different substituents on SAs degradation pathways. It was demonstrated that the geometrical differences among various SAs caused by the different substituents contributed to the different degradation pathways of SAs. Representatively, the special Smiles-type rearrangement pathway was occurred in the six-membered SAs instead of in the five-membered SAs, which inversely resulted in the slower degradation rate of six-membered SAs than the five-membered SAs. Thus, the present study provides a valuable insight into the effects of substituents on the degradation rate and transformation pathways of SAs in the nonradical PDS activation process.

The large consumption and discharge of antibiotic ciprofloxacin (CIP) force us to find an effective technology to removal of CIP. Herein, three dimensional (3D) tripyramid TiO2 architectures were eco-friendliness and facile synthesized with the assistance of aloe extracts and hydrothermal method and then were used in the photocatalytic removal of CIP pollutants. It’s found that residual biologically active components on the surface of TiO2 induced to the formation of 3D tripyramid architectures. The optimized composite showed a removal efficiency of 90% within 60 min. Compared to rod-like TiO2, 3D tripyramid TiO2 architectures displayed 3.4 times for photocatalytic degradation of CIP under UV–vis light irradiation. The present investigation initiates a green and eco-friendliness path for the construction of high-performance hierarchical catalysts in the application of wastewater purification.

Four types of dust samples and nine categories of locally produced staple foods were collected from a mega e-waste recycling industrial park and its surrounding regions, and simultaneously analyzed for short-chain and medium-chain chlorinated paraffins (CPs) to estimate dust and dietary exposure and their combined effects on occupational workers and local residents. All samples related to e-waste activities contained considerably high concentrations of CPs. The highest dust concentration was found in e-waste workshops. CPs were highly accumulated in local plant and animal origin foods, most markedly in fish, vegetables, and rice. The main contribution to CP intake under a median exposure scenario was from the diet, and vegetables, fish, and rice were the three largest dietary intake sources. Only the combined dust and food exposure from the present study has approached or even exceeded the highest tolerable daily intake (TDI) set up by the International Program on Chemical Safety (IPCS). However, due to lack of official threshold values for CP exposure on adverse human health, there are limitations on accurate risk assessment. Considering the presence of other exposure pathways, CPs' endocrine disrupter properties, as well as the multicomponent chemical "cocktails" effects, potential high risks from CP exposure may be posed to e-waste workers and local residents.

Fuel cells hold great potential of replacing traditional fossil fuel to alleviate the energy crisis and increasing environmental concerns. Although great progresses have been achieved over decades, the sluggish reaction kinetics and poor durability of electrocatalysts in fuel cells have been the decisive bottleneck that limited their practical applications. Herein, we focus on the design and development of cost-efficient anode electrocatalysts for fuel cells and report the successful creation of an advanced class of N-doped graphene (NG) supported binary PdAg nanocapsules (PdAg NCPs). The well-defined nanocatalysts with highly open structure exhibit greatly improved electrocatalytic performances for ethylene glycol oxidation reaction (EGOR). In particular, the optimized PdAg NCPs/NG show the mass and specific activities of 6118.3 mA mg−1 and 13.8 mA cm−2, which are 5.8 and 6.9 times larger than those of the commercial Pd/C catalysts, respectively. More importantly, such PdAg NCPs/NG can also maintain at least 500 potential cycles with limited catalytic activity attenuation, showing an advanced class of electrocatalysts for fuel cells.

Silver phosphate (Ag

In this work, a two dimensional (2D)/2D BiVO