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Pollution of Sb(III) in water has caused great concern in recent years. Nanoscale zero-valent iron (nZVI) can detoxify Sb(III) polluted water, but the rapid passivation and low adsorption capacity limit its practical application. Hence, this study provides a new and efficient nanotechnology to remove Sb(III) using the sulfidated nanoscale zero-valent iron (S-nZVI). The S-nZVI exhibits higher Sb(III)-removal efficiency than pristine nZVI under both aerobic and anoxic conditions. The adsorption capacity of Sb(III) by optimized S-nZVI (465.1 mg/g) is 6 times as high as that of the pristine nZVI (83.3 mg/g) under aerobic conditions. The results indicate that Sb(III) and Sb(V) can be immobilized on the surface of S-nZVI by forming Fe-S-Sb precipitates. Moreover, characterization results demonstrate that the existence of S2− can not only activate H 2 O 2 to produce hydroxyl radical, but also accelerate the cycle of Fe3+/Fe2+ to improve the efficiency of Fenton reaction. Therefore, S-nZVI can produce more hydroxyl radicals to oxidize Sb (III) to Sb (V) and results in 2.3-fold higher oxidation rate of Sb(III) compared to pristine nZVI. The formed FeS layer on the S-nZVI surface can also improve the release ability of Fe2+ and accelerate the formation of nZVI corrosion products. S-nZVI thus holds great potential to be applied in antimony removal. Unlabelled Image • The existence of S2− enhanced the oxidation ability of S-nZVI to Sb(III) • The cycle of Fe3+/Fe2+ was accelerated in S-nZVI system • The mechanism of antimony under aerobic or anoxic conditions were investigated [ABSTRACT FROM AUTHOR]

Quantum-sized cerium dioxide (CeO 2) show high catalytic capability as well as strong light absorption ability owing to its redox couple Ce4+/Ce3+ and abundant oxygen vacancies, which making it a potential material for designing superior photoelectrochemical (PEC) sensors. However, it has scarcely been applied in the field of PEC sensing, because its wide band gap and aggregation effect can restrict the photoelectric conversion efficiency. Herein, we address these two obstacles by coupling CeO 2 quantum dots (QDs) with graphitic carbon nitride (g-CN) and Au nanoparticles (NPs). The electron transfer path in this proposed heterojunction was proved by density functional theory (DFT) calculation for the first time, which provided theoretical support for the detection of MC-LR. The as-obtained PEC aptasensor exhibited excellent analytical performance with a wide liner response of 0.05–105 pM, and the detection limit was 0.01 pM. By designing appropriate sensing system and specific recognition mechanism, this work may pave a unique avenue for constructing ultrasensitive and selective analysis of MC-LR in complex environment without any external electric source. • CeO 2 was first applied in PEC sensing by designing an ACG heterostructure. • The electron transfer process in ACG heterostructure was proved by DFT calculation. • The specific recognition mechanism of aptamers makes this sensor more selective. • The accurate measurement of MC-LR in water samples by this sensor was obtained. [ABSTRACT FROM AUTHOR]

• An efficient and low-cost catalyst (Ca/BS-800-KOH) was successfully prepared. • Ca/BS-800-KOH showed good phenol removal rate with relatively low dose (0.066 g/L). • The mechanism of PS activation by Ca/BS-800-KOH was addressed. • Free and non-free radical pathways were proposed, where 1O 2 plays a key role. • Ca/BS-800-KOH/PS had a good application potential in organic wastewater treatment. Carbon-based catalysis for green and sustainable degradation of phenol in water and soil has attracted extensive concern. In this study, mesoporous biochar produced by bagasse calcination with KOH and CaCl 2 modified activation (Ca/BS-800-KOH) was used to stimulate persulfate (PS) for the surface oxidation degradation of phenol, which exhibited excellent removal rate of 90% in 60 min (k = 0.0404 min−1) with a relatively low dosage (0.066 g/L). Compared with untreated materials (BS-800, 27% removal rate in 180 min), after KOH and CaCl 2 treatment, the functional groups (C OH), increased porosity, defective structure and the more efficient electron transfer of Ca/BS-800-KOH were probably responsible for its good adsorptive and catalytic performance, which also closely related to the inactivation of Ca/BS-800-KOH. In the (Ca/BS-800-KOH)/PS/phenol system, PS was successfully activated in the presence of catalyst, and radical and non-radical reaction pathways were firstly found, in which the non-radical pathway like 1O 2 accelerated quickly the oxidative degradation of phenol. While in radical pathway involving SO 4 ·− and ·OH, ·OH was the main oxidative species and also played an irreplaceable role in the degradation of phenol. The Ca/BS-800-KOH as a medium promotes the electron transfer between phenol (electron donor) and PS (electron acceptor), in which Ca accelerates the electron transfer rate on the surface of Ca/BS-800-KOH, thereby causing oxidative degradation of phenol. The superior removal efficiencies of common environmental pollutants (all more than 93%) and phenol in water (100%) and soil samples were found. This research proposed an insightful mechanism of the low cost and feasible carbon-material-based PS-AOPs in degrading organic pollutants. [ABSTRACT FROM AUTHOR]

• Ultrathin 1D/2D W 18 O 49 /g-C 3 N 4 nanocomposites have been synthesized successfully. • 1D/2D W 18 O 49 /g-C 3 N 4 present high remove rate for IBF under light irradiation. • The LSPR effect of W 18 O 49 play vital role for the NIR light response ability. • h+, O 2 – and OH radical species are all participated in this reaction system. • Distinctive multiscale structure caused the promoted photocatalytic activity. Multi-level and multi-angle designations of photocatalysts have attracted great attention to address the insufficient photogenerated charge generation and transformation in photocatalysis. In this study, we reported an ultrathin 1D/2D W 18 O 49 /g-C 3 N 4 nanocomposites with unique multiscale structure and electronic property through direct growth of 1D plasmonic W 18 O 49 nanowires onto the surface of 2D ultrathin g-C 3 N 4 nanosheets. Owing to the unique multiscale structure and electronic property, the synthesized nanocomposites present enhanced photocatalytic activity, owns the maximum removal efficiency of 96.3% and rate constant of 0.0464 min−1 for Ibuprofen (IBF) after 60 min under AM 1.5G light. Meanwhile, under near-infrared (NIR) light irradiation, the optimum UWN-3 present 39.2% removal efficiency of IBF and the reaction rate reached 0.0027 min−1 after 120 min. Additionally, the degradation pathway indicated that the decarboxylation process was the main decomposition route of IBF in this reaction system, and OH radical species attack process also contributed to the degradation of IBF. Scavenge experiments and mechanism analysis illustrated that IBF degradation in this reaction system mainly depends on h+, O 2 – and OH radical species, and the promoted photocatalytic performance of the synthesized ultrathin 1D/2D W 18 O 49 /g-C 3 N 4 nanocomposites are stem from the synergism of the multichannel photogenerated charge transfer pathways. The combination of the multichannel charge transfer pathways mentioned above resulted in the highly efficient photocatalytic activity of the ultrathin 1D/2D W 18 O 49 /g-C 3 N 4 nanocomposites. [ABSTRACT FROM AUTHOR]

• A novel WO 3 @W 18 O 49 branched homojunction was fabricated for the first time. • The WO 3 @W 18 O 49 branched homojunction exhibit superior interfacial charge separation. • The enhanced interfacial charge separation was confirmed by series experiments. • A novel design strategy for full-spectrum responsive photocatalyst is proposed. • The degradation pathway of 2,4-DCP is proposed. Interfacial charge separation is a fundamental and crucial process in photoelectric conversion for composite photocatalyst. In this work, the interfacial charge separation performance was investigated on a nonmetallic branched homojunction, which is fabricated through solvothermal growth of W 18 O 49 nanofiber (as branches) onto WO 3 microrods (as backbones). The ultrafast transfer of photogenerated electrons from the WO 3 backbones to the W 18 O 49 branches across the contact interface was demonstrated by a series of experiments and characterizations. The contrast experiment showed that the WO 3 @W 18 O 49 homojunction exhibited superior interfacial electron transfer capacity to the BiVO 4 @W 18 O 49 heterojunction, the calculated interfacial charge separation efficiency of WO 3 @W 18 O 49 was 51.3%, which was more than twice as that of BiVO 4 @W 18 O 49 (24.2%). Upon localized surface plasmon resonance excitation by low-energy NIR photons, the full-spectrum light driven photo-degradation for 2,4-DCP was realized. The branched structure favors the enhancement of light scattering and absorbing. Meanwhile, the homojunction structure leads to a low impedance interface and increased electric conductivity. Thus, the WO 3 @W 18 O 49 exhibited an enhanced photocatalytic performance under both full-spectrum and NIR light irradiation. This work provides a promising approach to design and fabricate novel photocatalysts with full-spectrum response ability and enhanced charge separation. [ABSTRACT FROM AUTHOR]

Metal-free carbon materials (MFCMs), as newly emerging efficient catalysts in persulfate-based advanced oxidation process (PS-AOP), have exhibited great engineering-application potential for environmental remediation. Nevertheless, the relationships between discrepant catalytic properties and structural/surface characteristics of MFCMs are still ambiguous. Herein, on the basis of the recent advances in experimental and theoretical researches, we provide a systematic review to give insight into the relationships among catalytic activity, microstructure and electrical properties of MFCMs in PS-AOP, where the catalytic diversities of MFCMs in different configurations (sp2 , sp3 and amorphous) and dimensionalities (zero to three dimensional) are discussed in detail. Besides, the effects of different tailoring engineering approaches, such as structure defect, heteroatom doping, and regulation of pore structure and surface functional groups, on the catalytic activity of MFCMs in PS-AOP are thoroughly summarized. Finally, critical discussion and future prospects in the aspects of mechanism exploration and possible materials development are proposed to confront the existing challenges in the application of MFCMs in PS-AOP. [ABSTRACT FROM AUTHOR]

• A novel S-doped h -BN photocatalyst was fabricated for the first time. • The bandgap of h -BN can be adjusted by sulfur doping. • The DFT calculations were performed to investigate the change of band structure. • The charge mobility of h -BN was enhanced due to the compaction of interlayer stacking distance. Two-dimensional materials, especially metal-free two-dimensional materials such as graphene, carbon nitride and boron nitride have attracted significant attention for photocatalysis technology due to their unique charge mobility. Herein, S-doped h -BN with tunable band structure and layer stacking distance has been developed via a facile heat treatment strategy. Compared to the pristine h -BN, the optimized S-doped h -BN exhibited enhanced optical absorption, charge transfer, surface reactivity and hydrophilicity, which greatly improved its ability for photocatalytic degradation of 2,4-DCP. It is clearly demonstrated, by means of various experiments and characterizations, that the bandgap and layer spacing of h -BN can be adjusted by controlling the S doping amount. DFT calculations exposed that the p-orbitals and d-orbitals from sulfur are involved in the formation of the new valence and conduction band edges, which gradually reduced the CB potential, narrowed the bandgap and enhanced the optical absorption property of h -BN. And the shortened layer stacking distance and abundant S doping sites may be the main reason for the promotion of charge mobility and surface reactivity. Through this strategy, h -BN was vested with the ability of visible light response, which provides insights for the modification of other semiconductor materials with wide bandgap, and the study on the compression compaction phenomenon of interlayer stacking distance can open up a new feasible route to enhance charge mobility of other two-dimensional semiconductor materials. [ABSTRACT FROM AUTHOR]

The charge density wave (CDW) in transition metal dichalcogenides (TMDs) has drawn tremendous interest due to its potential for tailoring their surface electronic and chemical properties. Due to technical challenges, however, how the CDW could modulate the chemical behavior of TMDs is still not clear. Here, this work presents a study of applying the CDW of NbTe2, with a high transition temperature above room temperature, to generate the assembling adsorption of Sn adatoms on the surface. It is shown that highly ordered monatomic Sn adatoms with a quasi‐1D structure can be obtained under regulation by the single‐axis CDW of the substrate. In addition, the CDW modulated superlattices could in turn change the surface electronic properties from semimetallic to metallic. These results demonstrate an effective approach for tuning the surface chemical properties of TMDs by their CDWs, which could be applied in exploring them for various practical applications, such as heterogeneous catalysis, epitaxial growth of low‐dimensional materials, and future nanoelectronics. The charge density wave (CDW) of NbTe2 is applied to generate the assembling adsorption of Sn adatoms on the surface. The CDW modulated superlattices could in turn change the surface electronic properties from semimetallic to metallic. These results demonstrate an effective approach in tuning the surface chemical properties of transition metal dichalcogenide‐based materials by theirs CDWs. [ABSTRACT FROM AUTHOR]