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Green and highly selective synthesis of organonitrogen chemicals (ONCs) using the renewable energy source biomass over noble-metal free solid catalysts under common room temperature and pressure conditions is still a major challenge. Here, we report a sustainable electrochemical method for selective synthesis of several valuable ONCs with high yields using biomass-derived furanic aldehydes over greenly fabricated TiS2 nanosheets through a facile synthesis. Based on a range of characterization techniques including high-resolution transmission electron microscopy and X-ray absorption fine structure, a well-defined structure of the TiS2 nanosheets (3.86 nm with 1T phase) was constructed. These as-prepared catalysts were applied to the electrochemical reductive amination (ERA) of three biomass-derived aldehydes, i.e. furfural (FF), 5-methylfurfural (MF) and 5-hydroxymethylfurfural (HMF), and exhibited superior performance whereby over 95% conversion of each furanic aldehyde and nearly perfect selectivity of ONCs were achieved. TiS2 nanosheets, in particular, exhibited a marked ∼2-fold increase in conversion (∼49%) compared with the monometallic Ti electrode. Besides, the reaction kinetics and rational pathway were also studied. In addition, these exfoliated TiS2 nanosheets maintained high durability over 6 h, providing a promising and versatile route for the sustainable upgrading of biomass-derived sources. [ABSTRACT FROM AUTHOR]

How to efficiently and fast remove the serious perniciousness of the residual antibiotics in water environment is crucial for protecting ecosystem. Herein, we reported the Fenton-like system based on layered double hydroxides (LDHs) nanosheets for direct peroxymonosulfate (PMS) activation efficient for fast removing the typical five fluoroquinolones antibiotics ciprofloxacin (CIP), norfloxacin (NOR), levofloxacin (LEV), enrofloxacin (ENR) and ofloxacin (OFL). A series of CoFe-LDHs nanosheets was one-step fabricated by integrating coprecipitation and in-situ exfoliation method. The as-obtained CoFe-LDHs nanosheets catalysts exhibit thin nanosheets (~3 nm) with high redox properties, abundant oxygen vacancies, appreciable adsorption capacity, remarkable catalytic performance and favorable stability. The variable valent state, cheap, easy-to-obtain and low-toxic Co and Fe elements were used to construct stable LDHs for efficient activation of PMS to degrade quinolone antibiotics. Among them, Co 1 Fe 1 -LDHs nanosheets exhibited the best CIP degradation efficiency of 86.9% within 12 min, which is superior to most of previous candidates. The impacts of different reaction parameters, catalyst stability, main reactive oxygen species, the main CIP degradation mechanism and rational degradation pathways were systematically studied. This work offers a feasible strategy to tune the performance of LDHs-based materials in Fenton-like system degradation of antibiotics. [Display omitted] • A series of CoFe-LDHs nanosheets were used to activate PMS to degrade quinolones. • The structure-activity relationship of CoFe-LDHs was studied. • The Co 1 Fe 1 -LDHs/PMS/CIP system could degrade 86.9% CIP within 12 min. • Degradation mechanism and pathway of ciprofloxacin was proposed. [ABSTRACT FROM AUTHOR]

[Display omitted] • The garland-like MIL-101(Fe)/MoS 2 nanosheets activated PMS to degrade SMX. • .OH and 1O 2 were the dominant ROS in the MMS-0.1/PMS/SMX system. • Sulfur vacancies and Mo6+/Mo4+ sites accelerated the cycle of Fe3+/Fe2+. • Fukui index and LC-MS fully validated the rational degradation pathway of SMX. • The non-toxicity transformation of SMX was proved by toxicity analysis. Iron-based molybdenum disulfide (Fe-MoS 2) has emerged as a Fenton-like catalyst for the highly efficient degradation of antibiotics, but the structure–activity relationship remains elusive. Herein, garland-like MIL-101(Fe)/MoS 2 nanosheets (MMS) with dual metal active sites (Fe and Mo) and rich sulfur vacancies were fabricated to directly activate peroxymonosulfate (PMS) for fast degradation of different organic pollutants (phenols, dyes and drugs), even in real water bodies. The MMS exhibited extremely fast catalytic rate constant of 0.289 min−1 in the degradation of sulfamethoxazole (SMX), which was about 36 and 29 times that of single MoS 2 (0.008 min−1) and MIL-101(Fe) (0.01 min−1). Moreover, MMS with good stability and reusability could reach 92% degradation of SMX after 5 cycles. Quenching experiments and electron spin resonance (ESR) tests revealed that hydroxyl radicals (. OH) and singlet oxygen (1O 2) were the dominant reactive oxygen species (ROS) for SMX degradation. The integration of experimental works, characterization techniques and density functional theory (DFT) calculations unraveled that the formation of sulfur vacancies in MMS catalyst could expose more Mo sites, improve the charge density and boost the electron transfer, which was conducive to accelerating the Fe3+/Fe2+ cycle for enhancing the activation of PMS. Finally, the C-N, N-O, S-N, C-O and C-S bonds of SMX were easily attacked by ROS to generate the nontoxic intermediates in the MMS/PMS/SMX system. This study offers a new approach to designing high-performance Fe-MoS 2 catalysts for the removal of organic pollutants. [ABSTRACT FROM AUTHOR]

• The NCC (NiCo 2 O 4 grown on carbon) is developed as a robust photo-Fenton-like catalyst. • The synergistic effect between NC and carbon enhances the catalytic performance. • The NCC + PMS + L coupling system is universal for phenolic pollutants removal. • Degradation intermediates and removal mechanisms are identified and elucidated. Rational design of photocatalysts with the controllable structure to expose active sites is crucial to degrade phenolic pollutants. Herein, we report the in-situ synthesis of lily-like NiCo 2 O 4 nanosheets (0.95 nm) grown on waste biomass-derived carbon (abbreviated as NCC) for the highly efficient photocatalytic removal of phenolic pollutants through the integration of experiment and theory calculation. These as-fabricated NCC photocatalysts (2.29 nm) exhibit superior performance for the fast removal of phenolic pollutants (such as 4-Acetamidophenol (AP), phenol, and aspirin) in comparison with their counterpart and previously reported candidates. By using AP as a model molecule for mimicking pollutants, the photocatalytic degradation performance of NCC nanosheets is ∼ 1.3 and 1.9 times higher than that of pure NiCo 2 O 4 (NC) and porous carbon, respectively. Various factors that influenced the degradation process such as peroxymonosulfate (PMS) concentration, catalyst dosage, AP concentration, and initial pH are thoroughly investigated. The free radical quenching experiments and electron paramagnetic resonance (EPR) spectra further demonstrate the existence of SO 4 −·, ·OH, ·O 2 –, and 1O 2 in the reaction system and the ·O 2 – radical play a major role, which is also confirmed by the density functional theory (DFT) calculation. Several degradation pathways (e.g., demethylation, deacylation, hydroxylation, and ring-opening) are then proposed based on the detected intermediates. Finally, the high stability and good reusability of NCC nanosheets are confirmed via the degradation efficiency of over 85% even after five successive cycles. [ABSTRACT FROM AUTHOR]