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[Display omitted] Unevenly distributed polypyrrole (PPy) films/coatings with extensive "dead volumes" via electrodeposition have emerged as a main challenge for high energy density flexible supercapacitor. In this work, we have fabricated a phytic acid-guided graphite carbon felt/polypyrrole (GF@PA@PPy) 3D porous composite with less "dead volumes" via electrodeposition. After the activation of phytic acid (PA), the quantity and content of defects and oxygen-containing groups on the surface of carbon felt (GF) have increased. First, these functional groups improve the hydrophilicity of the surface of GF, resulting in the preferential uniform distribution of pyrrole monomer (Py). While significantly, the synergistic effects between the defects and oxygen-containing groups boost the attraction of pyrrole ring, and thus promotes the formation of perfect PPy films with less "dead volume" on GF. Finally, the supercapacitor assembled from the GF@PA@PPy-40 displays a high areal energy density of 0.0732 mWh cm−2, exceeding the previously reported PPy-based electrodes values. The deeper understanding of the role for the defects and oxygen-containing groups in the synthesis of PPy/carbon materials offers a new strategy to construct advanced PPy-based supercapacitors. [ABSTRACT FROM AUTHOR]

[Display omitted] • A multifunctional composite with MOFs-derived urchin-like amorphous carbon anchored on nickel foam was fabricated. • The asymmetric supercapacitor achieved a high energy density of 0.036 mWh cm−3 at a power density of 0.984 mW cm−3. • The used UAC@NF could be reutilized to recycle Pb (II) from sewage. • This "waste to wealth" way will have a remarkable impact on energy and the environment. The booming development of carbon materials is of great value for diverse applications, owing to their superior electron conductivity, unique structures, and excellent cycle lifetime. This study presents two hierarchically structured amorphous carbon materials for asymmetric supercapacitor (ASC) device: i) the MOFs-derived urchin-like amorphous carbon anchored on nickel foam (UAC@NF) as positive electrode; ii) high temperature activated graphite carbon felt (GF500) as negative electrode. This ASC device achieves a higher energy density of 0.036 mWh cm−3 at a power density of 0.984 mW cm−3 and demonstrates better cycling performance with 91.4% capacitance retention after 10,000 cycles, compared with the other carbon-based supercapacitor. In addition, the UAC@NF after 10,000 cycles displays much better adsorption performance for Pb (II) compared with the unused UAC@NF. We have demonstrated the relationship between carbon materials' structure and performance by combining experiment and theoretical calculation. Predominantly, our work can provide a new direction for the common development of amorphous carbon materials in the field of energy and environment. [ABSTRACT FROM AUTHOR]

• Graphene-based freestanding catalysts have renewed research interests. • Material and energy efficiencies are two important evaluation criteria for energy conversion and storage devices. • Surface and interface engineering can produce electronic conduction and active sites for energy storage devices. • Important synergy between different components can benefit capacitance performance. Next-generation energy storage methods are closely related to green recovery in the post-pandemic period and the future energy structure. Advanced graphene-based freestanding electrodes with highly tunable electronic structures and mechanical stability present superior electrochemical performance, which are among the most promising candidates for achieving efficient energy storage. However, the ever-increasing demand for energy has triggered significant room for the growth of material and energy efficiencies of graphene-based freestanding electrodes. Fortunately, their intrinsic reactivity can be improved by atomic-level tailoring of the surfaces and interfaces of electrodes. Therefore, there is an urgent need for researchers to grasp the relationship between the structure and electrochemical performance of graphene-based freestanding electrodes. In this review, we presented a focused discussion and multidimensional analysis of graphene-based freestanding electrodes, including the predictive design of valence electron structure, mechanistic understanding of conversion and storage, and performance evaluation in practical application. Moreover, future research aspects of the graphene-based freestanding electrodes are proposed. [ABSTRACT FROM AUTHOR]

Although the construction process of dual functional materials for dye and oil/water separation has been developed rapidly, the postprocess of the used separation materials themselves is still a problem owing to their non-degradation in the natural environment. Herein, novel porous membranes (PLA–PEI) are successfully prepared based on the utilization of a dip-coating technique. The adsorption isotherms and kinetics present a good correlation with Langmuir isotherms and the pseudo-second-order model, respectively. The maximum adsorption capacity of PLA–PEI for methyl orange (MO) can reach 455.10 mg g−1, which is approximately 78 times as much as that of PLA (5.82 mg g−1). In addition, the separation efficiencies of three actual oils (methylbenzene, hexamethylene and soybean oil) are all higher than 99.7%. Moreover, the obtained membranes can realize high-efficiency and simultaneous removal of MO (removal efficiency ＞ 99.8%) and oil droplets (oil rejection ＞ 99.7%) from mixed wastewater under a permeate flux of up to 8285 L m−2 h−1 solely driven by gravity. These results suggest that PLA–PEI is a promising and competitive candidate for water purification. [ABSTRACT FROM AUTHOR]

Abstract In this work, a biobased adsorbent (CMC-PAMA) consisting of sodium carboxymethyl cellulose, polyacrylic acid and polyacrylamide was prepared by a simple thermal crosslinking method for the removal of methylene blue (MB) and Pb (II) from aqueous solutions. The CMC-PAMA showed excellent static adsorption capacities for MB and Pb (II) of 1611.44 mg·g−1 840.11 mg·g−1, respectively, indicating its excellent performance on dyes dynamic removal. The adsorption performance of the as-prepared CMC-PAMA could be fitted well with pseudo-second-order and Langmuir isothermal model. The adsorption mechanism between CMC-PAMA and Pb (II) was confirmed by FT-IR, XPS and ion-exchange behavior. Interestingly, CMC-PAMA showed high efficiency for separation of MB/methyl orange (MO) mixtures, low equilibrium swelling ratio (0.52 g·g−1) in distilled water, good stability and reusability. With those combined advantages, CMC-PAMA could find potential application in wastewater treatment. Graphical abstract Unlabelled Image Highlights • Sodium carboxymethyl cellulose was masterly modified by a simple thermal crosslinking method. • The maximum adsorption capacities toward MB and Pb (II) were 1611.44 mg·g−1 and 840.11 mg·g−1. • The adsorbent displayed excellent filter capability for 50 mg·L−1 MB dynamic removal up to 8.5 L. • This adsorbent exhibited the outstanding stability and reproducibility. [ABSTRACT FROM AUTHOR]

[Display omitted] Recently, carbon materials have attracted much attention in activating persulfate (PS) for the removal of organic pollutants. Seeking a greener, lower-cost, and higher-performance carbon material has become an important aspect of research. In this study, candle soot was innovatively used as a nanocarbon material, and its performance for PS activation was improved by simple ammonium ferric citrate modification. The optimal catalytic performance was achieved using 0.15 g/L modified candle soot (AS) and only 0.1 mM PS, with sulfamethoxazole (SMX) removal efficiency up to 95.5% within 120 min. Quenching tests, together with electron paramagnetic resonance measurements, showed that O 2 − and 1O 2 were the main reactive species for SMX degradation. Meanwhile, electron transfer pathway was also occurred. Various characterization results showed that graphitic N and carbonyl group were the main active sites for PS activation. Moreover, AS/PS system exhibited high catalytic activity and stability for SMX degradation over a wide initial pH range (3∼9), or even in the presence of Cl−, H 2 PO 4 − and NO 3 −. This work not only taps the potential of candle soot as an environmental functional material, but also showcases the roadmap for the discovery, design, and resource utilization of other waste carbon materials in wastewater treatment. [ABSTRACT FROM AUTHOR]

Macrophyte rhizospheric dissolved organic matter (ROM) served as widespread abiotic components in aquatic ecosystems, and its effects on antibiotic residues and antibiotic resistance genes (ARGs) could not be ignored. However, specific influencing mechanisms for ROM on the fate of antibiotic residues and expression of ARGs still remained unclear. Herein, laboratory hydroponic experiments for water lettuce (Pistia stratiotes) were carried out to explore mutual interactions among ROM, sulfamethoxazole (SMX), bacterial community, and ARGs expression. Results showed ROM directly affect SMX concentrations through the binding process, while C O and N-H groups were main binding sites for ROM. Dynamic changes of ROM molecular composition diversified the DOM pool due to microbe-mediated oxidoreduction, with enrichment of heteroatoms (N, S, P) and decreased aromaticity. Microbial community analysis showed SMX pressure significantly stimulated the succession of bacterial structure in both bulk water and rhizospheric biofilms. Furthermore, network analysis further confirmed ROM bio-labile compositions as energy sources and electron shuttles directly influenced microbial structure, thereby facilitating proliferation of antibiotic resistant bacteria (Methylotenera, Sphingobium, Az spirillum) and ARGs (sul 1, sul 2, intl 1). This investigation will provide scientific supports for the control of antibiotic residues and corresponding ARGs in aquatic ecosystems. [Display omitted] • Amide and amino groups in ROM are main binding sites for sulfamethoxazole. • ROM bio-labile compositions are closely linked to microbial metabolisms. • ROM fractions favored the formation of rhizospheric biofilms. • SMX pressure stimulated the succession of bacterial community. • Rhizospheric biofilms offered favorable microenvironments for ARB development. [ABSTRACT FROM AUTHOR]

[Display omitted] • CoMoO@Co composite catalyst was successfully grown on graphite felt. • Metallic Co nanosheets drive amorphous to crystalline conversion in Co-Mo oxides. • The fabricated catalyst acts as a robust bifunctional electrocatalyst for the oxidation of water and urea. • The nanoflowers structure provides abundant and largely accessible catalytic active sites. • The coupling interface formed between metallic Co and Co-Mo oxides facilitates electron transfer in catalytic reaction. Oxygen evolution reaction (OER) and urea oxidation reaction (UOR) play important roles in the field of hydrogen energy preparation and pollution treatment. In this work, by merging bimetallic Co-Mo oxides with metallic Co on the graphite felt (GF), we effectively manufacture a 3D bifunctional and highly efficient electrocatalyst (CoMoO@Co/GF) with multi-site functionality for the simultaneous reduction of water and the oxidation of urea in an alkaline medium. The presence of metallic Co causes Co-Mo oxides to evolve from amorphous to crystalline structures. The coupling interface produced between metallic Co and Co-Mo oxides is proven to facilitate electron transport in addition to extensively accessible and highly electroactive Co-Mo oxide nanoflower architecture. The experimental results reveal that the overpotentials for OER and UOR in the CoMoO@Co/GF electrode require only 269 and 115 mV to obtain a current density of 10 mA cm−2, respectively. Furthermore, with the aid of urea, the overpotential for HER at the current density of 10 mA cm−2 is lowered to 155 mV. Most notably, the constructed CoMoO@Co/GF-based electrolytic cell only requires a 1.5 V dry battery to achieve effective H 2 evolution and noteworthy stability, outperforming the commercial catalyst-based device and many previous results. The combination of experiments and theoretical calculations further clarifies the active sites in the catalyst. What's more, the pathway of electron transfer in the catalytic process is defined. [ABSTRACT FROM AUTHOR]

[Display omitted] Heavy metal pollution in water bodies is a serious environmental problem continuously, which requires urgently seeking an efficient and cost-effective solution. Apatite as the most abundant phosphate on earth exhibits remarkable adsorption effect on heavy metals. Based on this, three kinds of apatite adsorbents were prepared in this study by titration co-precipitation method for the removal of heavy metals Pb (II) and Cd (II) from water. In the single system, the maximum adsorption capacity of hydroxyapatite (Hap), chlorapatite (Clap), and fluorapatite (Fap) for Pb (II) was 1597.16 mg/g, 1477.82 mg/g, and 1455.99 mg/g, for Cd (II) were Hap (107.18 mg/g), Clap (79.08 mg/g) and Fap (15.8 mg/g). Pb (II) was more competitive than Cd (II) in binary metal system. Apatite adsorbents mainly remove Pb (II) and Cd (II) from solution by dissolution precipitation, electrostatic attraction, surface complexation and ion exchange. The results of this study show that the three kinds of apatite adsorbents exhibited excellent adsorption performance for Pb (II), and also had a certain removal effect for Cd (II). Therefore, the three kinds of apatite have certain application prospects in heavy metal wastewater treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • The synthesis methods to incorporate N into zero-valent and atomic iron are systematically summarized. • The form of N and Fe changes after the incorporation of N. • The FeNx species play an important role in contaminants transformation. • The zero-valent and atomic iron after the incorporation of N can be promising materials for environmental application. The FeN x active species in Fe-N materials after the incorporation of N into zero-valent and atomic iron showed excellent performance on contaminants transformation compared with the materials before modification. However, the research of FeN x on the environmental field is still in the preliminary stage at present. In view of the enormous potential, this article emphasizes the research advances in the incorporation of N into zero-valent and atomic iron for contaminants transformation. Firstly, the synthesis of Fe-N material including synthesis methods, changes in characterization and active species as well as influence factors during the synthesis progress are introduced. Most importantly, the efficiency and mechanism of zero-valent iron after the N incorporation on dechlorination, denitrification and activation of oxidants, and the atomic iron after N incorporation on desulfurization, selective transformation and activation of oxidants are also summarized, where FeN x species play an important role. Additionally, due to the high stability, tolerance, adaptability to various contaminants and less recycling difficulty, the potential of Fe-N materials for practical environmental applications is appreciated. At length, this review discusses the challenges and overlooks in the future, looking forward to providing assistance for utilizing the Fe-N materials to handle the troublesome water contaminants. [ABSTRACT FROM AUTHOR]

The high active and stable 2D FeS/FeO x H@Fe nanoflakes with rich defects and disorders were fabricated by the introduction of FeS through a simple one-step electron-induced co-deposited mechanism. [Display omitted] Exploring earth-abundant catalysts with ultra-high activity and durability are the decisive challenges for oxygen evolution reaction. This work prepared the FeS/FeO x H@Fe nanosheets as the efficient and stable electrocatalysts of oxygen evolution reaction (OER) through a simple one-step co-deposition method. The FeS/FeO x H@Fe exhibited small overpotentials of 245, 376 and 482 mV at the current density of 10, 500 and 1000 mA cm−2 without iR-compensations in 1.0 M KOH solution, respectively. Constructing amorphous structure and the interface between amorphous and crystal can obviously improve the conductivity of FeO x H, which is beneficial to the improvement of catalytic performance. This work may provide an effective and controlled strategy to design highly active OER catalysts with an interface structure between amorphous and crystal by a well-designed co-deposition. [ABSTRACT FROM AUTHOR]

Graphical abstract Amorphous micro-tube/sphere architectures of hierarchical (Ni-Fe)S x /NiFe(OH) y films grown on nickel foam are fabricated via a simple one-step electron-induced co-deposited mechanism toward highly-efficient electrocatalytic overall water splitting at large current density. Highlights • Facile one-step electron-induced co-deposited strategy to fabricate hierarchically hollow micro-tube/sphere amorphous (Ni-Fe)S x /NiFe(OH) y films on Nickel foam. • Verifying bimetallic Ni-Fe chalcogenides and (oxy)-hydroxides are intrinsic HER and OER highly-catalytic species, respectively. • The amorphous (Ni-Fe)S x /NiFe(OH) y catalyst is one of the best bifunctional catalysts with cell voltage of 1.46 V at 10 mA·cm−2. • In inquasi-industrial environment, the bifunctional electrodes exhibit low electrolytic voltage of 2.2 V at large-current-density of 1200 mA·cm−2. Abstract Crystalline transition-metal chalcogenides with (oxy)-hydroxides hybrids multiple nanoarchitectures are a new type of promising bifunctional electrocatalysts for electrolysis of water, but their amorphous states are scarcely studied. Herein, a facile electrodeposited approach is presented to fabricate hierarchically amorphous (Ni-Fe)S x /NiFe(OH) y films on Nickel foam. By accurately tuning multi-components and electrochemical-parameters resulting in abundant micro-tube/sphere morphologies and phase evolution to obtain unique amorphous nano-cluster architectures, the (Ni-Fe)S x /NiFe(OH) y catalyst performs super electrocatalytic performance, driving the current density of 100 mA·cm−2 at ultralow overpotential of 124 mV and 290 mV for hydrogen and oxygen evolution reaction in 1 M KOH solution with first-class long-term stability for at least 50 h, respectively. In addition, the bimetallic Ni-Fe sulfides and NiFe hydroxides are confirmed to be highly-intrinsic active components for HER and OER. More importantly, the (Ni-Fe)S x /NiFe(OH) y material directly as cathode and anode electrodes, achieves 10 mA·cm−2 at low electrolytic voltage of 1.46 V in 1 M KOH, even at large current density of 1200 mA·cm-2 only needing 2.2 V as well as super-durability at 1000 mA·cm-2 for 50 h in quasi-industrial conditions. Further experimental results reveal that both temperature and appropriate alkalinity are in favour of reducing the overall hydrolytic overpotential due to accelerating sluggish thermodynamics and dynamics. Parallelly, the bifunctional (Ni-Fe)S x /NiFe(OH) y electrode is one of the best efficient electrocatalysts in alkaline electrolyte up to now and expected for large-scale industrial water-splitting at large-current-density. [ABSTRACT FROM AUTHOR]

Abstract Industrial spilled oil and oily wastewater have caused serious environmental pollution and energy dissipation. Hence, a robust cellulose-based filter paper-polyvinyl alcohol (cellulose-PVA) membrane for efficient oil-in-water emulsion separation was fabricated by a universal method of hydroxyl oxidation for any substrate containing hydroxyl groups that was cost-effective and easy to scale up. The resulting membrane exhibited superhydrophilicity, superoleophilicity in air, and stable superoleophobicity under various pH value solutions with contact angles exceeding 150°. The cellulose-PVA membrane can dispose of many types of surfactant-stabilized and different oil droplet sized oil-in-water emulsions with 98.75 % efficiency driven only by gravity without consideration the secondary processing problem. Furthermore, sand paper abrasion tests, tape peeling tests and chemical corrosion resistance tests were executed, indicating the excellent mechanical stability and superior durability of the cellulose-PVA membrane. These results suggest that it is a prospective and competitive candidate for industrial oil-in-water emulsion treatment. Graphical abstract A cellulose-based filter paper-polyvinyl alcohol membrane was fabricated by a universal method with good durability that is used to effectively separate various oil-in-water emulsions with high oil rejection under gravity. Image 1 Highlights • The fabrication method is universal for substrates with hydroxyl groups. • The membrane can separate different types and droplet sized oil-in-water feeds. • More than 99 % oil rejection was achieved driven by gravity. • The durability of cellulose-PVA membrane was better. [ABSTRACT FROM AUTHOR]

Developing versatile materials for simultaneous removal of organic dyes, heavy metals and oil from water has big significance for water protection. Herein, we fabricate a porous 3D polyurethane/polyacrylic acid (PU-PAA) membrane by simple solvent casting-salt leaching and thermal crosslinking, which combines the properties of underwater superoleophobicity and quantities of carboxyl groups. The stable superoleophobicity can be used for efficient surfactant-stabilized oil-in-water microemulsions separation. And the negative carboxylic ions are able to capture cationic dyes and heavy metals, simultaneously. Using the PU-PAA membrane in filtration column enables one-step multiple pollutants water treatment with high flux, selectivity, recyclability, efficiency and capacity. Moreover, PU-PAA can be used for efficient dye mixture separation. These results indicate that this versatile porous 3D membrane can be a very potential candidate for advanced purification applications. [ABSTRACT FROM AUTHOR]

Bio-absorbable magnesium alloys drug-eluting vascular scaffold was developed to resolve the defect of permanent metal and drug-eluting stents, most notably a chronic vessel wall inflammation and the risk of stent thrombosis. Nevertheless, violent chemical reaction and rapid degradation under physiological conditions limits their application. Furthermore, multifunctional drug-eluting stents which could reduce the formation of thrombus and repair the damaged vessels need more attention to fundamentally cure the coronary artery disease. Herein, a drug delivery system (Mg/MgO/PLA-FA) which can realize sustainable release of ferulaic acid was designed via anodic oxidation process and dip coating process. Electrochemical tests and immersion experiments showed that the superior anticorrosion behavior, it is due to the dense MgO-PLA composite layer. The released ferulaic acid can effectively decrease platelets adhesion and aggregation during the early stage of implantation. Besides, hemolysis tests showed that the composite coatings endowed the Mg alloy with a low hemolysis ratio. The Mg/MgO/PLA-FA composite materials may be appropriate for applications on biodegradable Mg alloys drug-eluting stents. [ABSTRACT FROM AUTHOR]

Success of biomimetic scaffold relies on the comparability of its microarchitecture and physicochemical properties to the natural bone. However, porous scaffolds which simultaneously possessed excellent mechanical properties, favorable bioactivity and tunable biodegradation were rarely reported. Herein, to integrate the high stiffness of hydroxyapatite (HA), the formability of lignocellulose (LG), the processability of poly(lactic acid) (PLA) and the bioactivity of sol-gel derived 58S bioactive glass (BG), poly(lactic acid) (PLA)-based composite scaffolds were fabricated by a simple technique of combining the solvent casting/particulate leaching and sol-gel method. The resultant scaffolds showed well-defined interconnected porous structure with pore size of 200–400 μm and rough pore wall, which was reported to be potentially beneficial for cell adhesion and ingrowth. In addition, the mechanical properties were obviously improved by the reinforcements of LG, HA, and BG. In vitro biomineralization studies indicated the incorporation of BG significantly enhanced the bioactivity of composite scaffolds. Specially, the degradation rate of scaffolds could be easily regulated by adjusting the BG content to match the regeneration of new bone. The developed PLA-based composite scaffolds might have a great potential for bone regeneration. [ABSTRACT FROM AUTHOR]

• We reported a Cu(OH) 2 -Cu/NF electrode, which can efficiently reduce nitrate. • The role of electrode in electrochemical reduction of nitrate was discussed. • The effects of various factors by the Cu(OH) 2 -Cu/NF electrode were studied. • The mechanism of nitrate reduction by the Cu(OH) 2 -Cu/NF electrode was studied. Nitrate (NO 3 −) pollution in natural water is severe and brings serious environmental and human health problems. With the rise of electrocatalytic NO 3 − reduction, highly reactive and selective electrodes are essential for the electrochemical reduction of NO 3 −. In this study, a one-step hydrothermal method was used to load Cu and Cu(OH) 2 on Ni foam (NF) (Cu(OH) 2 -Cu/NF) as a cathode. The system's unique design includes: Cu and Ni can promote the reduction of NO 3 − and the generation of active hydrogen atom (H*) as a reducing agent. Then, Cu(OH) 2 is beneficial to NO 2 − adsorption and promotes the reduction of NO 2 − intermediate. Finally, NH 4 + is oxidized to N 2 by reactive chlorine generated at the anode. The Cu(OH) 2 -Cu/NF electrode exhibits a 91.5 % conversion of NO 3 −-N in 90 min, which is 44 times higher than that of NF. Under 2000 mg/L Cl−, NH 4 + finally oxidizes to N 2 within 360 min, and N 2 selectivity is 95.60 %. In addition, the Cu(OH) 2 -Cu/NF electrode maintained an excellent electrochemical performance after 20 cycles. This study provided a new idea for designing efficient, stable, and inexpensive NO 3 − reduction electrodes. [ABSTRACT FROM AUTHOR]

[Display omitted] • The promoted generation strategies of 1O 2 in PS activation by modified-nZVI systems and nZVI-based coupling systems are summarized. • The influence factors on the generation and behavior of 1O 2 in nZVI/PS-based systems are reviewed. • The selectivity, wide pH adaptability and corresponding roles of 1O 2 in organic pollutants degradation are reviewed. • The challenges and prospects of 1O 2 generation in nZVI/PS-based systems are addressed. In recent years, the remediation of water contamination through non-radical pathways by singlet oxygen (1O 2) has caught scientists' increasing attention owing to the adaptability to wider pH range and superior selectivity to target pollutants. In this review, strategies of promoting the generation of 1O 2 in persulfate activation over nanoscale zero-valent iron (nZVI) and the corresponding roles of 1O 2 in degrading pollutants are summarized systematically, chiefly illustrating the mechanisms of persulfate activation to produce 1O 2. The reasons underlying improvements in the degradation of organic pollutants originate from increased generation and enhanced activity of 1O 2 in modified systems and coupling systems based on nZVI. Additionally, in order to figure out how external environment affects the generation and behavior of 1O 2 , several major influence factors are also compared and evaluated. On the whole, this paper draws a relatively clear picture of 1O 2 in the combination of persulfate and nZVI-based systems, opening novel perspective of capitalizing on the merits of 1O 2 to deal with the increasingly troublesome problem of water pollution. [ABSTRACT FROM AUTHOR]

In today's society, wastewater sludge has become solid waste, and the preparation of wastewater sludge into sludge biochar nanomaterials (SBCs) for resource utilization has become a promising method. SBCs have advantages over other biomasses, including their complex composition, wide range of raw materials, and especially the presence of various transition metals with catalytic properties. Heterogeneous Fenton processes using SBCs as catalyst carriers have shown great potential in the removal of pollutants. In this review, the synthesis methods of SBCs are reviewed and the effects of different synthesis methods on their physicochemical properties are discussed. Furthermore, the successful applications of raw SBCs, metal-modified SBCs, and Fenton sludge-SBCs in organic pollutant degradation, sediment remediation, and sludge dewatering are reviewed. The mechanisms occurring with different metals as active sites are explored, and the review shows that the degradation efficiency and stability of SBCs are very satisfactory. We also provide an outlook on the future development of SBCs. We hope that this review will help readers gain a clearer and deeper understanding of SBCs and promote the development of SBCs. [Display omitted] • Synthesis methods can affect the physicochemical properties of SBCs. • An overview of the mechanism and reusability of SBCs for pollutant degradation. • Summarized the application of SBCs in sludge dewatering. • Presented the challenges and prospects of SBCs in the Fenton-like field. [ABSTRACT FROM AUTHOR]

[Display omitted] • Microbial community and HGT are the key factors of ARGs changes. • Carbon-based materials and clay minerals can decontaminate ARGs and heavy metals. • Functional materials act as adsorbents and alleviate heavy metals to inhibit HGT. • Functional materials change microbial community to slow the VGT of ARGs. Antimicrobial resistance (AMR), especially antibiotic resistance, has posed a huge threat to public health. Moreover, heavy metal, another significant contaminant, can accelerate the generation and dissemination of AMR. Thus, the method and mechanism of AMR removal under heavy metal stress need to be elucidated urgently. Adsorption has been proved to be an important means to deal with AMR pollution. However, there is still a lack of systematic reviews on decontaminating the combined pollution of AMR and heavy metal by adsorption. With this in mind, this review introduces two types of adsorbents, carbon-based materials (biochar and graphene oxide) and clay minerals, which can remove antibiotic resistance genes (ARGs) efficiently even under heavy metal stress. Besides, we summarize the crucial factors affecting the variations of ARGs, and the mechanisms of ARGs removal by two materials under the influences of these factors are proposed. Then, the pathways of two materials to decrease ARGs by reducing heavy metal co-selection and altering microbial communities under heavy metal stress are emphasized. Finally, the bottlenecks of the research on reducing ARGs by these adsorbents and the prior study directions in the future are described in detail. To sum up, the review offers new insight into the mitigation of AMR and heavy metal pollution and facilitates the progress of feasible methods for the removal of ARGs and heavy metal. [ABSTRACT FROM AUTHOR]

[Display omitted] • Surface-modified bismuth vanadate is prepared for PMS activation under visible light. • CIP oxidation in BVO-2/PMS/Vis system is dominated by 1O 2 and photogenerated holes. • Surface C O acts as Lewis base site to induce PMS hydrolysis in acidic condition. • The efficiently separated electrons can reduce PMS for SO 4 − and OH generation. Lewis basic sites have been shown to induce singlet oxygen (1O 2) generation in metal-free catalysts while have yet to be elucidated in metal-containing bismuth vanadate (BiVO 4). Herein, surface-modified BiVO 4 photocatalysts are developed and applied in peroxymonosulfate (PMS) activation for ciprofloxacin (CIP) abatement employing 1O 2 and photogenerated holes as the primary reactive species. The surface carbonyl moiety acts as Lewis basic sites to induce PMS hydrolysis under acidic conditions for 1O 2 generation. The occurrence of electron transfer from PMS to catalyst accounts for 1O 2 generation via PMS oxidation. Moreover, PMS as an electron acceptor kinetically accelerates charge separation, not only inducing SO 4 − and OH generation but also allowing direct oxidation of CIP by efficiently separated holes. Accordingly, the optimal BVO-2/PMS/Vis system can completely degrade CIP in 9 min under visible light with a reaction rate of 0.4264 min−1, far exceeding the BVO-2/PMS (0.0063 min−1) and BVO-2/Vis (0.0411 min−1) systems. [ABSTRACT FROM AUTHOR]

Lignin exhibits some antioxidant and UV protection due to its large number of phenolic hydroxyl and methoxy groups, which can be used in the field of sun protection. However, its complex macromolecular structure, high polydispersity, low solubility and deep coloration limit their development in the sunscreen field. In this work, we purified and separated lignin by solvent fractionation so that its phenolic hydroxyl content could be retained or even increased without modification. Consequently, by controlling environmental factors, lignin rapidly self-assembles into nanospheres without changing its structure, which not only achieves the standard of light-colored lignin but also meets the requirement of high sunscreen performance. It was measured that the lignin nanospheres formed by this method could meet more than 90% of UV blocking, especially for ultraviolet (UVA) fragments, when mixed with commercially available creams. It not only promotes the application of lignin in the field of sun protection, realizes the sustainable development of lignin, but also alleviates the problem of solid waste treatment and disposal. [Display omitted] • Lignin fractions with different molecular weight, functional groups and solubility were obtained by solvent fractionation. • The union of solvent fractionation and self-assembly avoids the modification of lignin and promotes the synthesis of NPs. • Lignin sunscreens block UV rays up to 90% or more, especially for the UVA portion. • Compared with other methods for reducing lignin color rendering, it is simpler and environmentally friendly. • 30g of bamboo chips can meet the synthesis demand of sunscreen and realize the resource utilization of solid waste. [ABSTRACT FROM AUTHOR]

[Display omitted] • MOF-derived LDHs as transformations between functional materials are explored. • Three derivative approaches based on different mechanisms are interpreted. • The focus is on component changes and core–shell/hollow structure growth. • Applications in energy or environment-related fields are explored. • The challenges and directions of development are concluded. Template derivatization of metal–organic frameworks (MOFs) is regarded as an effective strategy for preparing structurally functionalized materials, but frequently generated metal–carbon compounds dramatically rely on energy-consuming and uncontrollable thermal treatments. In the last decade, another emerging trend is to grow layered double hydroxides (LDHs) from chemically treated MOF precursors, realizing a transformation of one functional material to another. Noteworthy, the surface grown LDHs effectively enhance the stability, electrical conductivity and mass transfer capability of MOFs, while the latter as three-dimensional structure supports to overcome the undesired aggregation of traditional LDHs. Besides, by incomplete/complete conversion, core–shell or hollow structures can also be facilely obtained, which is another point that has been explored for their unique merits including large surface area, low density and elastic cavity for reaction. This work summarizes the state-of-the-art progress of MOF-derived LDHs, which provides an earlier overview for their conversion and application. In the review, three different synthetic strategies are systematically organized and categorized, with special emphasis on elucidating their respective mechanisms. Based on the analysis of the compositional and structural advantages obtained from the derivation, the paper inspects the various applications of the materials in the energy and environment fields. This review aims to provide a systematic reference for MOF-derived LDHs and propose a deeper understanding of MOF derivatives. [ABSTRACT FROM AUTHOR]

[Display omitted] • An in-situ topological transformation way is proposed to synthesize ultrathin BiOCl. • BiOCl inherits the nanosheet structure and oxygen vacancies of the BiVO 4 precursor. • The oxygen vacancies endow BiOCl nanosheets with improved light-harvesting ability. • The oxygen vacancies promote charge carrier separation and prolong carrier lifetime. • 5.0 and 3.5 times increase in CIP removal rate and O 2 − yield are achieved in BiOCl. Herein, a facile in-situ topological transformation where BiVO 4 nanosheets (NS) with open instead of closed and inert surface are used as template and original material for the preparation of ultrathin BiOCl NS is proposed. The BiOCl NS developed in this work not only inherits the two-dimensional nanosheet structure of the BiVO 4 precursor, but also exhibits improved light-harvesting ability in the meantime as a result of the retention of oxygen vacancies during the topological transformation. The defect state mediated by oxygen vacancies under the conduction band endows BiOCl a narrower forbidden band width as compared to its bulk counterpart, which extends its light absorption range from ultraviolet to visible light region. More importantly, oxygen vacancies can also act as cocatalyst to accept photogenerated electrons excited from the valence band of BiOCl, which greatly suppresses the recombination of electron-hole pairs and prolongs the carrier lifetime, thereby promoting the activation of molecular oxygen into superoxide radicals (O 2 −) under visible light irradiation. As expected, the optimal BiOCl-3 NS exhibits a 2.2-fold increase in the yield of O 2 − radicals compared with bulk-BiVO 4. Furthermore, a large amount of free H+ in the waste acid wastewater can be tightly adsorbed with the terminal oxygen atoms of the (0 0 1) facet of BiOCl to compensate for its dangling bonds, which inhibits the crystal growth along the c axis, leaving highly reactive (0 0 1) facets as the dominant facets. Thanks to these merits, BiOCl-3 displays the highest photocatalytic performance towards ciprofloxacin (CIP) degradation among all samples, with the corresponding degradation rate of 4.51 times higher than that of the bulk-BiVO 4 , and the apparent quantum efficiency of 0.411%. Moreover, the as-developed BiOCl NS has excellent stability even after five successive cycles, with no significant changes in photocatalytic activity and structure, showing its good potential in practical applications. [ABSTRACT FROM AUTHOR]

• The fabrication of metal-based QD-decorated functional materials was provided. • The importance and controllability of QDs loading were clarified. • The protection of QDs in modified functional materials was conducted from the perspective of passivation. • The roles of QDs in the decorated functional materials was provided. In this review, we provided a systematic progress which focused on the synthesis of metal chalcogenide/oxide-based QD-decorated functional materials for photoelectrocatalysis and photovoltaic cells application. First, a brief introduction about the surface characteristics of QDs was elaborated. Then, based on the general synthesis mechanism and strategies for QDs, a comprehensive analysis on the present situation for the fabrication of metal chalcogenide/oxide-based QD-decorated functional materials was provided from three new perspectives, namely, in-situ growth of QDs onto pre-fabricated functional materials, post-synthesis assembly of QDs on functional materials, and co-growth of QDs and substrate materials. Moreover, the pros and cons of each strategy were discussed. Particularly, the QD-based heterophase junction structures were described separately due to their special configuration. From the perspective of photoelectric performance, the controllability and importance of QDs loading were emphasized. Further, a comprehensive analysis for the protection of QDs in modified functional materials was conducted from the perspective of passivation. Additionally, based on the synthesis strategy, a systematic classification and analysis of the roles of QDs in the decorated functional materials was provided. Finally, we concluded by providing an insight for future development of QD-based functional materials in photoelectrochemistry. [ABSTRACT FROM AUTHOR]

• Defects engineering strategies and advanced characterization techniques of bimetallic Ni-based catalysts are discussed in detail. • Defects engineering in bimetallic Ni-based catalysts is discussed separately from introducing defects into the pre-synthesized bimetals and creating defects directly during the synthesis of bimetallic catalysts. This review describes the latest developments in defects engineering of bimetallic Ni-based catalysts for electrochemical energy conversion. First, the classification and roles of defects are introduced. Furthermore, defects engineering strategies and advanced characterization techniques of bimetallic Ni-based catalysts are discussed in detail. Taking the typical and most widely studied three types of bimetallic Ni-based (Ni-Fe, Ni-Co and Ni-Mo) materials as examples, defects engineering in bimetallic Ni-based catalysts is discussed separately from introducing defects into the pre-synthesized bimetals and creating defects directly during the synthesis of bimetallic catalysts. What's more, a brief analysis of defects diffusion problems in bimetallic system is presented. Finally, a personal outlook about bimetallic defects chemistry is proposed. This review is intended to provide an important insight into the relationship between the defect chemistry of bimetallic Ni-based materials and their catalytic activity, meanwhile, it also provides a theoretical basis for new advances in other bimetallic catalysts. [ABSTRACT FROM AUTHOR]

The design of large-scale and stable bifunctional electrocatalyst with excellent activities at large current density is one of the powers to promote the development of industrial water electrolysis. In this work, a super-hydrophilic non-noble metal electrocatalyst, Ni 3 P/MnOOH, was prepared by electrochemical tuning on Ni 3 P/Mn precursor that was grown firstly on 3D porous conductive nickel foam substrate by electrodeposition. The Ni 3 P/MnOOH hybrid catalyst displays high electrocatalytic activity that requires a low overpotential of 268 mV and 341 mV at 1000 mA cm−2 for hydrogen evolution reaction and oxygen evolution reaction in simulated industrial environment, respectively. Remarkably, an alkaline electrolyzer constucted by Ni 3 P/MnOOH hybrid electrode as the anode and cathode only require a cell voltage of 1.53 V at 10 mA cm−2 with prominent stability under above half-reaction condition. This work not only improves the OER activity of catalysts with good HER performance, but also provides a broad prospect for its application in large-scale electrolytic water. [ABSTRACT FROM AUTHOR]