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C 3 N 4 is a promising visible-light-driven photocatalyst with superior chemical stability and photostability. The intrinsic problem associated with its use is that recombination of photogenerated electron-hole pairs slows down the industrial process. We designed novel C 3 N 4 /CdS/MoS 2 sandwich hybrids to increase the carrier utilization efficiency according to well-matched band alignment. The smart arrangement of C 3 N 4 -CdS-MoS 2 led to step-by-step electron/hole pair separation. Meanwhile, the conductive layer MoS 2 supported the easy surface transfer of electrons. The higher coefficient of separation and transfer results in a more effective reduction of electron/hole pair recombination compared to previous work. The Rhodamine B (RhB) photodegradation rate constant for the hybrids is considerably enhanced compared to pure C 3 N 4 , from 0.0309 to 0.0533 min−1. The strategy of loading separation/transfer bifunctional cocatalysts can be widely used to maximize the solar utilization efficiency of other photocatalysts. Unlabelled Image • A novel ternary C 3 N 4 /CdS/MoS 2 sandwich structure has been designed and synthesized. • The visible light driven degradation of RhB over C 3 N 4 /CdS/MoS 2 was studied. • The step-by-step charge transfer mechanism on C 3 N 4 /CdS/MoS 2 was proposed. [ABSTRACT FROM AUTHOR]

In this study, magnetic biochar (MAB) and humic acid (HA)-coated magnetic biochar produced from apple branches without and after cellulase hydrolysis (HMAB and CHMAB, respectively) were prepared and tested as adsorbents of enrofloxacin (ENR) and moxifloxacin (MFX) in aqueous solution. Compared with MAB and HMAB, novel adsorbent CHMAB possessed a superior mesoporous structure, greater graphitization degree and abundant functional groups. When antibiotic solutions ranged from 2 to 20 mg L−1, the theoretical maximum adsorption capacities of CHMAB for ENR and MFX were 48.3 and 61.5 mg g−1 at 35 °C with adsorbent dosage of 0.4 g L−1, respectively, while those of MAB and HMAB were 39.6 and 54.4 mg g−1, and 44.7 and 59.0 mg g−1, respectively. The pseudo-second-order kinetic model and Langmuir model presented a better fitting to the spontaneous and endothermic adsorption process. The maximum adsorption capacity of ENR and MFX onto CHMAB was achieved at initial pH values of 5 and 8, respectively. Additionally, the adsorption capacity of ENR and MFX decreased with increasing concentrations of K+ and Ca2+ (0.02–0.1 mol L−1). Synergism between the pore-filling effect, π-π electron-donor-acceptor interactions, regular and negative charge-assisted H-bonding, surface complexation, electrostatic interactions and hydrophobic interactions may dominate the adsorption process. This study demonstrated that a novel magnetic biochar composite prepared through pyrolysis of agricultural waste lignocellulose hydrolyzed by cellulase in combination with HA coating was a promising adsorbent for eliminating quinolone antibiotics from aqueous media. [Display omitted] • HA-coated magnetic biochar from cellulase hydrolysis biomass (CHAMB) was prepared. • Cellulase hydrolysis promoted pyrolysis and graphitization of the biochar precursor. • CHMAB exhibited superior adsorption capacity for ENR and MFX from water. • Pore-filling, π-π, H-bonding, electronic and group interactions dictated adsorption. • Adsorbent separation and efficient antibiotic removal were achieved together. [ABSTRACT FROM AUTHOR]

Solar-driven reduction of nitrogen to ammonia is a promising strategy for energy storage and conversion. Herein, a new strategy of modifying Fe(III) onto carbon nitride is reported showing enhanced photocatalytic nitrogen fixation. The Fe(III) and nitrogen vacancies narrow down the carbon nitride intrinsic bandgap and suppress the radiative electron-hole recombination. Fe(III)-C 3 N 4 therefore shows potential as a new high-efficiency artificial photosynthesis ammonia. Image 1 • A new strategy of preparing enriched N-vacancy C 3 N 4 by introducing Fe(III) is developed. • The high separation rate of electron-hole and broad bandgap of C 3 N 4 are achieved. • The Fe(III)-C 3 N 4 effectively enhances the visible-light nitrogen photofixation activity. [ABSTRACT FROM AUTHOR]

Developing ZnO photoanodes with high light-harvesting efficiency is of great importance for building photoelectrochemical (PEC) cells. Utilization of light in visible region is always an obstacle because of the wide band gap of ZnO. We constructed a ternary hierarchical semiconductor consisting of ZIF-8/67 encapsulated ZnO nanorod arrays (ZnO-NAs) on FTO substrate that showed high efficient visible-light-driven PEC water splitting. This ZnO@ZIF-8/67 photoanode exhibited a photocurrent density of 0.11 mA cm −2 at 1.23 V ( vs . Reversible Hydrogen Electrode), which was 9.2 times higher than that of the pristine ZnO-NAs, thanks to the fast one-dimensional electron transportation along ZnO nanorods and the intense visible-light absorption of ZIF-67. This work presents a promising pathway of fabricating MOF-based semiconductor composites for high performance water splitting and solar energy capture. [ABSTRACT FROM AUTHOR]

The recently developed techniques for desalination and wastewater treatment are costly and unsustainable. Therefore, a cost-effective and sustainable approach is essential to achieve desalination through wastewater treatment. Capacitive deionization (CDI), an electrochemical desalination technology, has been developed as a novel water treatment technology with great potential. The electrode material is one of the key factors that promotes the development of CDI technology and broadens the scope of CDI applications. Biochar-based electrode materials have attracted increasing attention from researchers because of their advantages, such as environmentally friendly, economical, and renewable properties. This paper reviews the methods for preparing biochar-based electrode materials and elaborates on the mechanism of CDI ion storage. We then summarize the applications of CDI technology in water treatment, analyze the mechanism of pollutant removal and resource recovery, and discuss the applicability of different CDI configurations, including hybrid CDI systems. In addition, the paper notes that environmentally friendly green activators that facilitate the development of pore structure should be developed more often to avoid the adverse environmental impact. The development of ion-selective electrode materials should be enhanced and it is necessary to comprehensively assess the impact of heteroatoms on selective ion removal and CDI performance. Electrooxidation of organic pollutants should be further promoted to achieve organic degradation by extending to redox reactions. [Display omitted] • Activation, templating, heteroatom doping and metal oxide loading have been shown to be effective means of improving the electrochemical properties of biocarbon-based materials. • The ion storage mechanism of CDI involves EDL ion storage and Faraday pseudocapacitance storage. • The applicability of CDI technology in the field of water treatment has been proven. • Electrooxidation of organic pollutants should be further promoted to achieve simultaneous organic degradation by extending to redox reactions. [ABSTRACT FROM AUTHOR]