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For the efficient degradation of organic pollutants with the goal of reducing the water environment pollution, we employed an alkaline hydrothermal treatment on primeval g-C 3 N 4 to synthesize a hydroxyl-grafted g-C 3 N 4 (CN-0.5) material, from which we engineered a novel Fenton-like catalyst, known as Cu–CN-0.5. The introduction of numerous hydroxyl functional groups allowed the CN-0.5 substrate to stably fix active copper oxide particles through surface complexation, resulting in a low Cu leaching rate during a Cu–CN-0.5 Fenton-like process. A sequence of characterization techniques and theoretical calculations uncovered that interfacial complexation induced charge redistribution on the Cu–CN-0.5 surface. Specifically, some of the π electrons in the tris-s-triazine units were transferred to the copper oxide particles along the newly formed chemical bonds (C (π) -O-Cu), forming a π-deficient area on the tris-s-triazine plane near the complexation site. In a typical Cu–CN-0.5 Fenton-like process, a stable π-π interaction was established due to the favorable positive-negative match of electrostatic potential between the aromatic pollutants and π-deficient areas, leading to a significant improvement in Cu–CN-0.5's adsorption capacity for aromatic pollutants. Furthermore, pollutants also delivered electrons to the Cu–CN-0.5 Fenton-like system via a "through-space" approach, which suppressed the futile oxidation of H 2 O 2 in reducing the high-valent Cu2+ and significantly improved the generation efficiency of •OH with high oxidative capacity. As expected, Cu–CN-0.5 not only exhibited an efficient Fenton degradation for several typical aromatic organic pollutants, but also demonstrated both a low metal leaching rate (0.12 mg/L) and a H 2 O 2 utilization rate exceeding 80%. The distinctive Fenton degradation mechanism substantiated the potential of the as-prepared material for effective wastewater treatment applications. [Display omitted] • A unique interfacial regulation strategy for Enhancing Fenton activity. • Effective adsorption of pollutants by Fenton catalyst achieved through π-π Stacking. • Expanding novel theoretical computational methods to Fenton reaction domain. • The system significantly improved the H 2 O 2 utilization and the.•OH generation efficiency. [ABSTRACT FROM AUTHOR]

Recently, highly efficient activation of peroxymonosulfate (PMS) by S-doped cobalt-based catalysts are receiving increased attention. The effect of S is worth exploring since it has a great influence on PMS activation performance. In this work, dimethyl sulfoxide was adopted as an S source and loaded on bamboo biochar (BB) with Co to form CoS/BBC, which served as an efficient catalyst for PMS activation to degrade sulfamethoxazole (SMX). The experiment results showed that CoS/BBC exhibits an excellent catalytic activity and the SMX (20 mg/L) can be completely degraded under the attack of species of · OH, SO 4 - · , 1O 2 and electron transfer. The SMX degradation conformed to pseudo first-order kinetics with rate constant reaching 0.442 min−1 in 10 min under the optimal conditions (a catalyst dose of 0.02 g/L, a PMS dose of 0.3 g/L and an initial pH = 7.0). The electrochemical experiments and density functional theory (DFT) calculation revealed that the introduction of S can accelerate electron transfer and promote the decomposition of PMS while facilitating Co(III)/Co(II) redox cycling. Furthermore, liquid chromatograph-mass spectrometer (LC-MS) and ecological structure activity relationships (ECOSAR) proved that the degradation process of SMX in CoS/BBC/PMS system has low ecotoxicity and is harmless to the environment. This work provides a new strategy for enhancing electron transfer by S-doped metal materials and the synthesis of efficient catalysts for SMX removal. [Display omitted] • CoS/BBC/PMS system presented > 99% removal efficiency within 10 min. • S accelerated electron transfer and promoted Co(III)/Co(II) redox cycling. • Effects of anions and dissolved organic matters on PMS activation were studied. • SMX degradation pathways were proposed and verified by LC-MS and DFT. • Sulfamethoxazole degradation in this system was a toxicity-attenuation process. [ABSTRACT FROM AUTHOR]

Every city in the world faces pollution problems caused by traffic congestion almost every day. Platinum group elements (PGE) have been accumulating in the urban environment as catalytic converters for automobile exhaust emissions control. This study aims to determine the temporal variations of airborne particulate matter (PM)-bound PGE [Platinum (Pt), palladium (Pd) and rhodium (Rh)] in areas close to traffic congestion hotspots. Compared with the morning peak time, the concentrations of Pt, Pd, and Rh in outdoor airborne PM samples (PM 2.5) collected in winter during the evening peak time increased by 35.03%, 37.45% and 75.47%, respectively, and the corresponding indoor environment was 9.33%, 6.93% and 71.36%, respectively. Significant temporal variations of PM 2.5 -bound Pt, Pd, and Rh concentrations were observed during the time period of the Spring Festival. From before to during the Spring Festival, the outdoor environment Pt, Pd, and Rh concentrations sharply decreased by 172.1%, 14.72% and 22.96%, respectively, while the indoor environment decreased by 228.0%, 300.6% and 129.5%, respectively. From a seasonal perspective, among PM 2.5 collected from the outdoor environment, PGE concentrations are the highest in winter and the lowest in summer. The temporal variation of the ratios (Pt/Pd, Pt/Rh, and Pd/Rh) indicates that PM 2.5 -bound Pd concentration increased in the vicinity of traffic congestion. Further, the increased diesel-based trucks with Pt-dominant catalytic converters may contribute to PM 2.5 -bound Pt detected in the autumn and winter of the alpine area (e.g. Harbin). Image 1 • Traffic congestion has a substantial impact on the distribution of PGE in PM 2.5. • Palladium had the highest relative concentrations in PM 2.5. • Materials transportation characteristics impact PGM ratio in PM 2.5. [ABSTRACT FROM AUTHOR]

[Display omitted] • Downstream waste-to-hydrogen process can be realised with 2D material-based membrane. • Mechanism and fabrication methods of 2D material-based gas separation membrane are outlined. • 2D COFs, MOFs and carbon-based materials are reviewed for H 2 /CO 2 gas separation membranes. • Challenges and future prospect of 2D material-based membrane in waste-to-hydrogen are discussed. Waste management has become an ever-increasing global issue due to population growth and rapid globalisation. For similar reasons, the greenhouse effect caused by fossil fuel combustion, is leading to chronic climate change issues. A novel approach, the waste-to-hydrogen process, is introduced to address the concern of waste generation and climate change with an additional merit of production of a renewable, higher energy density than fossil fuels and sustainable transportation fuel, hydrogen (H 2) gas. In the downstream H 2 purifying process, membrane separation is one of the appealing options for the waste-to-hydrogen process given its low energy consumption and low operational cost. However, commercial polymeric membranes have hindered membrane separation process due to their low separation performance. By introducing novel two-dimensional materials as substitutes, the limitation of purifying using conventional membranes can potentially be solved. Herein, this article provides a comprehensive review of two-dimensional materials as alternatives to membrane technology for the gas separation of H 2 in waste-to-hydrogen downstream process. Moreover, this review article elaborates and provides some perspectives on the challenges and future potential of the waste-to-hydrogen process and the use of two-dimensional materials in membrane technology. [ABSTRACT FROM AUTHOR]

The hybrid membrane bioreactor - nanofiltration treatment process can be an effective approach for treating the landfill leachate, but the residual leachate concentrate highly loaded with the humic substance and salts remains an environmental concern. Herein, a loose nanofiltration membrane (molecular weight cut-off of 860 Da) was used to recover the humic substance, which can act as a key component of organic fertilizer, from the leachate concentrate. The loose nanofiltration membrane showed the high permeation fluxes and high transmissions (>94.7%) for most inorganic ions (i.e., Na+, K+, Cl−, and NO 3 −), while retaining 95.7 ± 0.3% of the humic substance, demonstrating its great potential in effective fractionation of humic substance from inorganic salts in the leachate concentrate. The operation conditions, i.e., cross-flow rates and temperatures, had more pronounced impacts on the filtration performance of the loose nanofiltration membrane. Increasing cross-flow rates from 60 to 260 L h−1 resulted in an improvement of ca. 7.3% in the humic substance rejection, mainly due to the reduced concentration polarization effect. In contrast, the solute rejection of the nanofiltration membrane was negatively dependent on the temperature. The rejection of humic substance decreased from 96.3 ± 0.3% to 92.0 ± 0.4% with increasing the temperature from 23 to 35 °C, likely due to the enlargement of the membrane pore size and enhancement in solute diffusivity. The humic substance was enriched from 1735 to 15,287 mg L−1, yielding a 91.2% recovery ratio with 85.7% desalination efficiency at a concentration factor of 9.6. The recovered HS had significantly stimulated the seed germination and growth of the green mungbean plants with no obvious phytotoxicity. These results demonstrate that loose nanofiltration can be an effective promising technology to recover the humic substance as a valuable fertilizer component towards sustainable management of the landfill leachate concentrate. Image 1 • Loose nanofiltration (NF) membrane was used for sustainable treatment of leachate concentrate. • Loose NF can effectively separate humic substance (HS) and salts in leachate concentrate. • NF concentration process can significantly enrich and harvest HS with 85.7% salt removal. • The recovered HS stimulated the plant growth, presenting a potential as water-soluble fertilizer. [ABSTRACT FROM AUTHOR]

CdS quantum dots (QDs) are excellent visible-light-driven photocatalysts due to their unique small size (<10 nm), suitable band energy structure, and short charge transportation length. Unfortunately, the easy aggregation of CdS QDs to form larger particles results in a higher recombination rate for photoinduced electron-hole pairs, which deteriorates the photocatalytic activity. Here, we report in situ growth of CdS QDs with high dispersion and stability on covalent triazine-based frameworks (CTFs) via a facile photoreduction method. The photocatalytic H 2 evolution activity of CdS QD-loaded CTFs is effectively enhanced to approximately 55 and 4 times than that of pristine CTFs and bulk CdS, respectively. This enhanced photocatalytic performance is mainly ascribed to the higher separation rate of photogenerated carriers resulting from synergistic QD-on-sheet interactions between CdS QDs and CTFs. This work develops an efficient one-pot strategy to prepare metal-sulfide QDs with high dispersion and underlines the potential of utilizing CTFs as a suitable platform to develop efficient photocatalytic systems. • ● The growth of CdS QDs on CTF-1 was achieved by a facile in situ photoreduction method. • The CdS QD-loaded CTF-1 showed higher H 2 evolution activity over pristine CTF-1 and bulk CdS. • The enhanced photocatalytic activity was mainly ascribed to the higher separation of the carriers. • The higher separation was due to the synergistic QD-on-sheet interactions between CdS QDs and CTF-1. [ABSTRACT FROM AUTHOR]

• Superhydrophobic PVDF membrane was fabricated by spray-coating of fluorinated SiO 2 NPs. • Superhydrophobic PVDF membrane had a water contact angle of 171.8 ± 1.1° and sliding angle of 1.69 ± 0.13°. • The modified PVDF membrane maintained stable superhydrophobicity under harsh conditions. • The prepared membrane has consistent separation efficiencies up to 99.88 ± 0.03% in water-in-oil emulsions over 40 cycles. • Scale-up fabrication of superhydrophobic PVDF membrane was successfully performed. Hydrophobic anti-wetting membranes have many applications, such as oily wastewater treatment via oil/water separation, desalination via membrane distillation, and carbon capture via gas-liquid membrane contactors. Herein, we used a simple and scalable method to fabricate robust superhydrophobic polyvinylidene fluoride (PVDF) based membranes by one-step spray-coating of fluorinated SiO 2 nanoparticles. The prepared PVDF membrane was systematically characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy and contact angle measurements. The modified PVDF membrane had excellent superhydrophobicity with an extremely high water contact angle up to 171.8 ± 1.1° and a low sliding angle of 1.69 ± 0.13°, due to the fluorinated close-packed hydrophobic SiO 2 nanoparticles on the surface. The modified PVDF membrane maintained its relatively stable superhydrophobicity under various harsh conditions, i.e., exposure in hot water, NaOH and HCl, ultrasonication and high-speed flushing, indicating the superior robustness and stability. The prepared membrane also exhibited consistent separation efficiencies up to 99.88 ± 0.03% in water-in-oil emulsions, and superior recyclability and durability over 40 cycles. In addition, spray-coating showed its great promise in engineering various superhydrophobic surfaces on different substrates and excellent scalability in fabricating large-size membranes. This study demonstrates a facilely scalable spray-coating method for engineering robust superhydrophobic surfaces and membranes that can be potentially used for various gas, vapor and water/oil separations. [ABSTRACT FROM AUTHOR]