Hierarchical coral-like FeNi(OH)_x/Ni via mild corrosion of nickel as an integrated electrode for efficient overall water splitting

Efficient,stable,and noble‐metal‐free electrocatalysts for both the oxygen evolution reaction and the hydrogen evolution reaction are highly imperative for the realization of low‐cost commercial water‐splitting electrolyzers.Herein,a cost‐effective and ecofriendly strategy is reported to fabricate coral‐like FeNi(OH)x/Ni as a bifunctional electrocatalyst for overall water splitting in alkaline media.With the assistance of mild corrosion of Ni by Fe(NO3)3,in situ generated FeNi(OH)x nanosheets are intimately attached on metallic coral‐like Ni.Integration of these nanosheets with the electrodeposited coral‐like Ni skeleton and the supermacroporous Ni foam substrate forms a binder‐free hierarchical electrode,which is beneficial for exposing catalytic active sites,accelerating mass transport,and facilitating the release of gaseous species.In 1.0 mol L^-1 KOH solution,a symmetric electrolyzer constructed with FeNi(OH)x/Ni as both the anode and the cathode exhibits an excellent activity with an applied potential difference of 1.52 V at 10 mA cm^-2,which is superior to that of an asymmetric electrolyzer constructed with the state‐of‐the‐art RuO2‐PtC couple(applied potential difference of 1.55 V at 10 mA cm^-2).This work contributes a facile and reliable strategy for manufacturing affordable,practical,and promising water‐splitting devices.

Electro-catalytic oxidation of phenol with Ti-base lead dioxide electrode

The Ti base PbO 2 electrode prepared by electrodeposition of PbO 2 on the surface of titanium was used for electro catalytic oxidation of phenol in waste water. The experimental results show that the electrodeposition of PbO 2 at a higher current density for a short time, then followed by a lower current density can get a compact and combinative PbO 2 layer. The properties of a Ti/PbO 2 electrode with an interlayer of oxide are the best. When this kind of electrode is used to treat phenol containing waste water, the phenol removal rate is higher and the slot voltage is lower. In addition, by using the phenol removal rate as an index, the influences of electrolysis current density, mass transfer condition and pH were studied and the optimal condition was confirmed.

Advanced municipal wastewater treatment and simultaneous energy/resource recovery via photo(electro)catalysis

Wastewater management and energy/resource recycling have been extensively investigated via photo(electro)catalysis.Although both operation processes are driven effectively by the same interfacial charge,each system is practiced separately since they require very different reaction conditions.In this review,we showcase the recent advancements in photo(electro)catalytic process that enables the wastewater treatment and simultaneous energy/resource recovery(WT-ERR).Various literatures based on photo(electro)catalysis for wastewater treatment coupled with CO_(2)conversion,H_(2)production and heavy metal recovery are summarized.Besides,the fundamentals of photo(electro)catalysis and the influencing factors in such synergistic process are also presented.The essential feature of the catalysis lies in effectively utilizing hole oxidation for pollutant degradation and electron reduction for energy/resource recovery.Although in its infancy,the reviewed technology provides new avenue for developing next-generation wastewater treatment process.Moreover,we expect that this review can stimulate intensive researches to rationally design photo(electro)catalytic systems for environmental remediation accompanied with energy and resource recovery.

水在金属硫化矿体自燃中的作用

金属硫化矿物氧化起因于硫化矿石固液相界面的电化学反应。水是硫化矿石自热、自燃的关键。注水、石灰水及其他阻化剂的阻燃方法忽视了水溶液中游离氧在硫化矿物氧化过程中所起的巨大作用，因而收效甚微。注水对自燃的矿石有一定的物理降温作用，但对未燃矿石则起了电化学升温作用，对深部矿体则起了预热预氧化作用。

Sulphur vacancy defects engineered metal sulfides for amended photo(electro)catalytic water splitting: A review

Vacancy engineering in metal sulfides has garnered enormous attention from researchers because of their outstanding ability to modulate the optical and physiochemical properties of photocatalysts.Typically,in the case of sulfides,the catalytic activity is drastically hindered by the quick reassembly of excitons and the photocorrosion effect.Hence designing and generating S-vacancies in metal sulfides has emerged as a potential strategy for attaining adequate water splitting to generate H_(2) and O_(2) because of the simulta-neous improvement in the optoelectronic features.However,developing efficient catalysts that manifest optimal photo(electro)catalytic performance for large-scale applicability remains challenging.Therefore,it is of utmost interest to explore the insightful features of creating S-vacancy and study their impact on catalytic performance.This review article aims to comprehensively highlight the roles of S-vacancy in sulfides for amended overall water-splitting activity.The photocatalytic features of S-vacancies modulated metal sulfides are deliberated,followed by various advanced synthetic and characterization techniques for effectual generation and identification of vacancy defects.The specific aspects of S-vacancies in refin-ing the optical absorption range charge carrier dynamics,and photoinduced surface chemical reactions are critically examined for overall water splitting applications.Finally,the vouchsafing outlooks and op-portunities confronting the defect-engineered(S-vacancy)metal sulfides-based photocatalysts have been summarized.

Boosting multi-hole water oxidation catalysis on hematite photoanodes under low bias

The accumulation of multiple surface holes is considered to be the key to efficient photoelectrochemical(PEC)water oxidation.Previous PEC water oxidation studies commonly apply high potentials(>1.2 VRHE)to achieve this key.But how to complete multi-hole transfer under low bias(<1.2 VRHE)remains unknown.Herein,we find that,on a typical visible-light photoanode,hematite(α-Fe_(2)O_(3)),UV excitation plays a indispensable role in driving multi-hole water oxidation under low bias.Compared with the visible-light excitation,the UV excitation promotes the formation of adjacent surface-trapped holes onα-Fe_(2)O_(3) at 0.9VRHE,thereby increasing the reaction order of surface holes from~1 to~2 and improving the PEC water oxidation activity by one order of magnitude.The UV irradiation reduces the formation probability of self-trapped excitons and results in~3 to 5-fold increase of surface holes.These advantages enable the UV excitation to contribute about 40%to the total photocurrent under 1 solar illumination,even though its energy only occupies 6%of the incident light.This mechanism is also applicable to boost selective two-hole oxidation of thioether at 0.1 VFc/Fc+and nitrite at 0.9 VRHE.

3D Hierarchical Carbon‑Rich Micro‑/Nanomaterials for Energy Storage and Catalysis

Increasing concerns over climate change and energy shortage have driven the development of clean energy devices such as batteries,supercapacitors,fuel cells and solar water splitting in the past decades.And among potential device materials,3D hierarchical carbon-rich micro-/nanomaterials(3D HCMNs)have come under intense scrutiny because they can prevent the stacking and bundling of low-dimensional building blocks to not only shorten diffusion distances for matter and charge to achieve high-energy-high-power storage but also greatly expose active sites to achieve highly active,durable and efficient catalysis.Based on this,this review will summarize the synthetic strategies and formation mechanisms of 3D HCMNs,including 3D nanocarbons,polymers,COFs/MOFs,templated carbons and derived carbon-based hybrids with a focus on 3D superstructures such as urchins,flowers,hierarchical tubular structures as well as nanoarrays including nanotube,nanofiber and nanosheet arrays.This review will also discuss the application of 3D HCMNs in energy storage and catalysis systems,including batteries,supercapacitors,electrocatalysis and photo(electro)catalysis.Overall,this review will provide a comprehensive overview of the recent progress of 3D HCMNs in terms of preparation strategies,formation mechanisms,structural diversities and electrochemical applications to provide a guideline for the rational design and structure–function exploration of 3D hierarchical nanomaterials from different sources beyond carbon-based species.

Precise electro-reduction of alkyl halides for radical defluorinative alkylation

Reported here is a precise electro-reduction strategy for radical defluorinative alkylation towards the synthesis of gem-difluoroalkenes from α-trifluoromethylstyrenes. According to the redox-potential difference of the radical precursors, direct or indirect electrolysis is respectively adopted to realize the precise reduction. An easy-to-handle, catalyst-and metal-free condition is developed for the reduction of alkyl radical precursors that are generally easier to be reduced than α-trifluoromethylstyrenes,while a novel electro-Ni-catalytic system is established for the electro-reduction of alkyl bromides or chlorides towards the electrochemical synthesis of gem-difluoroalkenes. The merit of this protocol is exhibited by its mild conditions, wide substrate scope, and scalable preparation. Mechanistic studies and DFT calculations proved that the coordination of α-trifluoromethylstyrenes to Ni-catalyst prevents the direct reduction of the alkene and, in turn, promotes the activation of alkyl bromide through halogen atom transfer mechanism.

Two-dimensional polymer nanosheets for efficient energy storage and conversion

As a promising graphene analogue,two-dimensional(2D)polymer nanosheets with unique 2D features,diversified topological structures and as well as tunable electronic properties,have received extensive attention in recent years.Here in this review,we summarized the recent research progress in the preparation methods of 2D polymer nanosheets,mainly including interfacial polymerization and solution polymerization.We also discussed the recent research advancements of 2D polymer nanosheets in the fields of energy storage and conversion applications,such as batteries,supercapacitors,electrocatalysis and photocatalysis.Finally,on the basis of their current development,we put forward the existing challenges and some personal perspectives.

High-entropy oxides as energy materials:from complexity to rational design

High-entropy oxides(HEOs),with their multi-principal-element compositional diversity,have emerged as promising candidates in the realm of energy materials.This review encapsulates the progress in harnessing HEOs for energy conversion and storage applications,encompassing solar cells,electrocatalysis,photocatalysis,lithium-ion batteries,and solid oxide fuel cells.The critical role of theoretical calculations and simulations is underscored,highlighting their contribution to elucidating material stability,deciphering structure-activity relationships,and enabling performance optimization.These computational tools have been instrumental in multi-scale modeling,high-throughput screening,and integrating artificial intelligence for material design.Despite their promise,challenges such as fabrication complexity,cost,and theoretical computational hurdles impede the broad application of HEOs.To address these,this review delineates future research perspectives.These include the innovation of cost-effective synthesis strategies,employment of in situ characterization for micro-chemical insights,exploration of unique physical phenomena to refine performance,and enhancement of computational models for precise structure-performance predictions.This review calls for interdisciplinary synergy,fostering a collaborative approach between materials science,chemistry,physics,and related disciplines.Collectively,these efforts are poised to propel HEOs towards commercial viability in the new energy technologies,heralding innovative solutions to pressing energy and environmental challenges.