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Electrocatalytic conversion of biomass‐derived 5‐hydroxymethylfurfural (HMF) to value‐added 2,5‐furandicarboxylic acid (FDCA) is of great significance in compensating for the rapid consumption of fossil resources. However, it is a challenge to further improve the performance of HMF electrocatalytic oxidation (HMFOR) by synergistic kinetics (active sites) and thermodynamics (adsorption sites). In this work, Al(OH)3/Co(OH)2 is successfully fabricated as an efficient catalyst, and its catalytic mechanism for HMF oxidation is clarified. Extended X‐ray absorption fine structure (EXAFS) analysis demonstrate that electrochemically generated Co3+ is the main catalytic site for HMF oxidation. The HMF equilibrium adsorption capacity of Al(OH)3 reach 57.0 mg g−1, which effectively increase the initial concentration of substrate and promoted the reaction rate. The combined results, based on 24 stable cycles and an FDCA yield retention rate of 98.6% after 180 days, are the highest ever achieved. Additionally, it is shown that this system can oxidize four other biomass‐derived substrates. Therefore, this work provides insight into a hydroxide catalyst that owes its efficiency to synergy between active and adsorption sites. [ABSTRACT FROM AUTHOR]

To induce the generation of active species at the metal–carrier interface, a new synthetic strategy was successfully developed to reconstruct the Ni MOF–Au via electrochemical activation. This unique configuration not only obtained high-valence NiOOH–Au3+ species, but also stably anchored the Au nanoparticles on the surface of the catalyst. As a result, nearly 99.8% FDCA yield and 100% Faraday efficiency of FDCA were achieved at the optimal potential of 1.57 V vs. RHE. Therefore, this electrochemical reconstruction provides new insights for the development of efficient catalysts in other heterogeneous catalytic reactions. [ABSTRACT FROM AUTHOR]

Electrocatalytic nitrate reduction reaction (EC-NITRR) shows a significant advantage for green reuse of the nitrate (NO 3 - ) pollutant. However, the slow diffusion reaction limits the reaction rate in practical EC-NITRR, causing an unsatisfactory ammonia (NH 3 ) yield. In this work, a multifunctional NiFe-LDH/CeO 2 with the dual adsorption effect (physisorption and chemisorption) and dual-metal sites (Ce 3+ and Fe 2+ ) was fabricated by the electrodeposition method. NiFe-LDH/CeO 2 performed an expected ability of enrichment for NO 3 - through the pseudo-first-order and pseudo-second-order kinetic models, and the polymetallic structure provided abundant sites for effective reaction of NO 3 - . At-0.6 V vs RHE, the ammonia (NH 3 ) yield of NiFe-LDH/CeO 2 reached 335.3 μg h -1 cm -2 and the selectivity of NH 3 was 24.2 times that of NO 2 - . The nitrogen source of NH 3 was confirmed by 15 NO 3 - isotopic labeling. Therefore, this work achieved the recycling of the NO 3 - pollutant by synergy of enrichment and catalysis, providing an alternative approach for the recovery of NO 3 - from wastewater.

To induce the generation of active species at the metal-carrier interface, a new synthetic strategy was successfully developed to reconstruct the Ni MOF-Au via electrochemical activation. This unique configuration not only obtained high-valence NiOOH-Au 3+ species, but also stably anchored the Au nanoparticles on the surface of the catalyst. As a result, nearly 99.8% FDCA yield and 100% Faraday efficiency of FDCA were achieved at the optimal potential of 1.57 V vs. RHE. Therefore, this electrochemical reconstruction provides new insights for the development of efficient catalysts in other heterogeneous catalytic reactions.

The conversion of organic pollutants to value-added chemicals has been considered as a sustainable approach to solve environmental problems. However, it is still a challenge to construct a suitable heterogeneous catalyst that can synchronously achieve the enrichment and activation of organic pollutants (such as 4-nitrophenol, 4-NP). Here, an organic-inorganic hybrid catalyst (CeO 2 /Ni-MOF) was successfully fabricated for efficiently reducing 4-NP to 4-aminophenol (4-AP) with water as the hydrogen source. Based on the synergistic effect of Ni-MOF (adsorption action) and CeO 2 (active sites), CeO 2 /Ni-MOF could achieve a reaction rate of 1.102 μmol min -1 mg -1 with an ultrahigh Faraday efficiency (FE) (99.9%) and conversion (97.6%). In addition, the catalytic mechanism of 4-NP reduction over CeO 2 /Ni-MOF was elaborated in depth. This work presents a new avenue for the effective reduction of pollutants and provides a new strategy for designing high-performance catalysts for rare-earth metals.

Achievement of the intrinsic activity by in situ electrochemical reconstruction has been becoming a great challenge for designing a catalyst. Herein, an effective electrochemical strategy is proposed to reconstruct the surface of the CF-CuO/CeO 2 precursor. Under the stimulation of oxidative/reductive potential, abundant active sites were successfully generated on the surface of CF-CuO/CeO 2 . Remarkably, the implantation of oxygen vacancy-rich CeO 2 synergistically optimizes the chemical composition and electronic structure of CF-CuO/CeO 2 , greatly promoting the generation of active species. Systematic electrochemical experiments indicate that the superior catalytic performance of reconstructed CF-CuO/CeO 2 could be attributed to CuOOH/CeO 2 and Cu 2 O/Ce 2 O 3 active species, respectively. The oxidative-/reductive-activated CF-CuO/CeO 2 was further employed in a paired cell for the synergistic catalysis of hydroxymethylfurfural oxidation with 4-nitrophenol hydrogenation. As a result, nearly 100% Faraday efficiency for furandicarboxylic acid/4-aminophenol production was achieved in the paired system (-0.9 V vs Ag/AgCl, 1.5 h). Therefore, the electrochemical reconstruction via oxidative/reductive activation has been confirmed as a feasible approach to significantly excite the intrinsic activity of a catalyst.

Hg 2+ ions are one of the highly poisonous heavy metal ions in the environment, so it is urgent to develop rapid and sensitive detection platforms for detecting Hg 2+ ions. In this work, a novel electrochemical and photoelectrochemical dual-mode sensor (l-Cys-Cu 2 O) was successfully fabricated, and the sensor exhibits a satisfactory detection limit (0.2 and 0.01 nM) for the detection of Hg 2+ , which is far below the dangerous limit of the U.S. Environmental Protection Agency. The linear ranges of dual-mode Hg 2+ detections were 0.33-3.3 and 0.17-1.33 μM, respectively. Moreover, the sensor shows desirable stability, selectivity, and reproducibility for detecting Hg 2+ ions. For river water samples, the recoveries of 96.6-101.4% (electrochemical data) and 93.0-105.6% (photoelectrochemical data) were obtained, indicating that the sensor could be successfully applied in the determination of Hg 2+ ions in environmental water. Therefore, the designed sensor has a potential in the trace-level detection of Hg 2+ ions.