A combined experimental and theoretical approach revealing a direct mechanism for bifunctional water splitting on doped copper phosphide

Facilitated Visible-Light-Driven Peroxymonosulfate Activation by a Co-Fe Layered Double Hydroxide Derived p-n Heterostructure for Sulfadiazine Degradation: Affecting Parameters, Kinetics, and Mechanistic Insights

The utilization of multivalence ionic metal species generated through a peroxymonosulfate (PMS)-assisted photocatalytic system is a promising platform for the selective degradation of water contaminants. However, achieving an effective electron transport and enhanced separation efficiency for these metal species is a daunting challenge. Thus, our current study addresses this challenge by using a Co-Fe-based layered-double-hydroxide template to synthesize a Co3O4/FeCo2O4 p-n heterojunction composite via a simple monosynthetic route. The resultant composite is thoroughly validated through advanced characterization techniques that efficiently activate PMS for sulfadiazine (SDZ) degradation under visible light, achieving a remarkable degradation efficiency of up to 90%. This accomplishment is attributed to factors including intimate interfacial contact, excellent light harvesting, mesoporosity, and oxygen vacancies within the composite. The formation of a distinct p-n heterojunction following the S-scheme charge dynamic significantly enhances photogenerated carrier separation and reduces charge recombination. The research delves into comprehensive investigations including degradation studies, active species trapping experiments, parameter exploration, and in-depth liquid chromatography-mass spectrometry for analysis of the degradation byproducts and pathway. Induced oxygen vacancies, strategically placed active surface sites, and mesoporosity in the Co3O4/FeCo2O4 composite synergistically boosted the sluggish PMS activation, leading to enhanced SDZ degradation. This study introduces a new perspective by demonstrating the potential of a single-material, mixed-metal oxide-based p-n heterojunction photocatalytic system following the S-scheme charge-transfer route for SDZ degradation. The findings contribute toward emphasizing the importance of tailored composite materials in tackling persistent contaminants.

The Recent Progresses of Electrodes and Electrolysers for Seawater Electrolysis

The utilization of renewable energy for hydrogen production presents a promising pathway towards achieving carbon neutrality in energy consumption. Water electrolysis, utilizing pure water, has proven to be a robust technology for clean hydrogen production. Recently, seawater electrolysis has emerged as an attractive alternative due to the limitations of deep-sea regions imposed by the transmission capacity of long-distance undersea cables. However, seawater electrolysis faces several challenges, including the slow kinetics of the oxygen evolution reaction (OER), the competing chlorine evolution reaction (CER) processes, electrode degradation caused by chloride ions, and the formation of precipitates on the cathode. The electrode and catalyst materials are corroded by the Cl- under long-term operations. Numerous efforts have been made to address these issues arising from impurities in the seawater. This review focuses on recent progress in developing high-performance electrodes and electrolyser designs for efficient seawater electrolysis. Its aim is to provide a systematic and insightful introduction and discussion on seawater electrolysers and electrodes with the hope of promoting the utilization of offshore renewable energy sources through seawater electrolysis.

S-Scheme ZIF-67/CuFe-LDH Heterojunction for High-Performance Photocatalytic H2 Evolution and CO2 to MeOH Production

The S-scheme heterojunction photocatalyst holds potential for better photocatalysis owing to its capacity to broaden the light absorption range, ease electron-hole separation, extend the charge carrier lifespan, and maximize the redox ability. In this study, we integrate zeolitic imidazolate frameworks (ZIFs-67) with the CuFe-LDH composite, offering a straightforward approach towards creating a novel hybrid nanostructure, enabling remarkable performance in both photocatalytic hydrogen (H2) evolution and carbon dioxide (CO2) to methanol (MeOH) conversion. The ZIF-67/CuFe-LDH photocatalyst exhibits an enhanced photocatalytic hydrogen evolution rate of 7.4 mmol g-1 h-1 and an AQY of 4.8%. The superior activity of CO2 reduction to MeOH generation was 227 μmol g-1 h-1 and an AQY of 5.1%, and it still exhibited superior activity after continuously working for 4 runs with nearly negligible decay in activity. The combined spectroscopic analysis, electrochemical study, and computational data strongly demonstrate that this hybrid material integrates the advantageous properties of the individual ZIF-67 and CuFe-LDH exhibiting distinguished photon harvesting, suppression of the photoinduced electron-hole recombination kinetics, extended lifetime, and efficient charge transfer, subsequently boosting higher photocatalytic activities.

Amorphous NiCuFeP@Cu3P nanoarray for an efficient hydrogen evolution reaction

Transition metal phosphides are considered as ideal alternatives for noble metal catalysts for hydrogen evolution reactions. In this study, amorphous NiCuFeP nanosheets are uniformly coated on self-supporting Cu3P nanowire array...

Selenium-induced NiSe2@CuSe2 hierarchical heterostructure for efficient oxygen evolution reaction

Electrochemical water splitting is widely studied in the hope of solving environmental deterioration and energy shortage. The design of inexpensive metal catalysts exhibiting desired catalytic performance and durable stability for efficient oxygen evolution is the pursuit of sustainable and clean energy fields. Herein, a three-dimensional (3D) flower-like NiSe₂ primary structure, modified with highly dispersed CuSe₂ nanoclusters as the secondary structure, is obtained by regulating the growth trend of the nanosheets. Benefiting from the metallicity of selenides and the formation of a heterogeneous interface, NiSe₂@CuSe₂/NF shows comparable performance toward the oxygen evolution reaction (OER) in an alkaline environment. Upon regulating the synthesis conditions, the catalyst exhibits its optimal performance with ultralow overpotential for the OER when the Ni/Cu molar ratio is 1 : 0.2 and the hydrothermal temperature and hydrothermal time are 200 °C and 6 h, respectively. It provides a current density of 10 mA cm^-2 when a potential of 201 mV is applied without iR compensation. In this work, the hierarchical heterostructures of NiSe₂ and CuSe₂ are synthesized, which exhibit high electrocatalytic activity towards the oxygen evolution reaction and provides a new possibility for the extensive application of copper-based compounds in advanced energy fields.