Modification Of Electronic Structure Research Articles

Curvature Effect of Pyridinic N-Modified Carbon Atom Sites for Electrocatalyzing CO2 Conversion to CO.

Carbon material is considered a promising electrocatalyst for the CO2 reduction reaction (CO2RR); especially, N-doped carbon material shows high CO Faradic efficiency (FECO) when using pyridinic N species as the active site. However, in the past decade, more efforts were focused on the preparation of various carbon nanostructures containing abundant pyridinic N species and few researchers studied the electronic structure modulation of the pyridinic N site. The curvature of the carbon substrate is an easily controllable parameter for modulating the local electronic environment of catalytic sites. In this research, carbon nanotubes (CNTs) with different diameters are applied to modulate the electronic environment of pyridinic N by the curvature effect. The pyridinic N sites doped on CNTs with the average curvature of 0.04 show almost 100% FECO at the current density of 3 mA cm-2 at -0.6 V vs RHE and 91% FECO retention after 12 h test, which is superior to most of the carbon-based electrocatalysts. As demonstrated by density functional theory simulation, the pyridinic N site forms a strong local electric field around the nearby C active site and protrudes out of the curved CNT surface like a tip, which remarkably enriches the protons around the adsorbed CO2 molecule.

Surface Electronic Structure Engineering of Manganese Bismuth Tellurides Guided by Micro-Focused Angle-Resolved Photoemission.

Modification of the electronic structure of quantum matter by ad atom deposition allows for directed fundamental design of electronic and magnetic properties. This concept is utilized in the present study in order to tune the surface electronic structure of magnetic topological insulators based on MnBi2 Te4 . The topological bands of these systems are typically strongly electron-doped and hybridized with a manifold of surface states that place the salient topological states out of reach of electron transport and practical applications. In this study, micro-focused angle-resolved photoemission spectroscopy (microARPES) provides direct access to the termination-dependent dispersion of MnBi2 Te4 and MnBi4 Te7 during in situ deposition of rubidium atoms. The resulting band structure changes are found to be highly complex, encompassing coverage-dependent ambipolar doping effects, removal of surface state hybridization, and the collapse of a surface state band gap. In addition, doping-dependent band bending is found to give rise to tunable quantum well states. This wide range of observed electronic structure modifications can provide new ways to exploit the topological states and the rich surface electronic structures of manganese bismuthtellurides.

The electronic structure modification and photocatalytic ability improvement of Rb0.9Nb1.625Mo0.375O5.62 β-pyrochlore compound

The photocatalytic ability of Rb0.9Nb1.625Mo0.375O5.62 UV-photocatalyst has been improved by electron structure modifications. The Rb0.75Cu0.15Nb1.625Mo0.375O5.6 and Rb0.8Mn0.1Nb1.625Mo0.375O5.7 modified compounds and Rb0.9Nb1.625Mo0.375O5.62/SnO2 heterostructure photocatalyst have been obtained under hydrothermal conditions. The crystal structure and elemental composition have been confirmed by X-ray diffraction analysis and X-ray microanalysis. The electron structure of the obtained samples has been investigated in comparison to initial one by diffuse reflection spectroscopy. All prepared samples possess the absorption in visible light range; however significant photocatalytic activity shows only Rb0.9Nb1.625Mo0.375O5.62/SnO2 heterostructure. The kinetic study of methylene blue photooxidation for Rb0.9Nb1.625Mo0.375O5.62/SnO2 at neutral pH have been investigated. It has been observed that the main oxidative species for dye oxidation are holes, hydroxyl radicals and superoxide radicals. The products of MB degradation have been determined by HPLC-MS method, and possible pathway of oxidation has been proposed.

Modulation of Electron Structure and Dehydrogenation Kinetics of Nickel Phosphide for Hydrazine‐Assisted Self‐Powered Hydrogen Production in Seawater

AbstractThe electrocatalytic production of hydrogen from seawater provides a low‐cost way to realize energy conversion, but is restricted by high potential for seawater electrolysis and the chlorine oxidation reaction (ClOR) at the anode. Here, the self‐growth of Mo‐doped Ni2P nanosheet arrays with rich P vacancies on molybdenum‐nickel foam (MNF) (Mo‐Ni2Pv@MNF) is reported as bifunctional catalyst for Cl‐free hydrogen production by coupling hydrogen evolution reaction (HER) with hydrazine oxidation reaction (HzOR) in seawater. Impressively, the Mo‐Ni2Pv@MNF electrode as bifunctional catalyst has an excellent activity for overall hydrazine splitting (OHzS) with an ultralow voltage of only 571 mV at 1000 mA cm−2 and can maintain stability for an ultra‐long time of 1000 h at 100 mA cm−2. Moreover, integration of OHzS into self‐assembled hydrazine fuel cells (DHzFC) or solar cells can enable the self‐powered H2 production. The industrial hydrazine sewage as feed for the above eletrolysis system can be degraded to ≈5 ppb rapidly. Density functional thoery calculations demonstrate that the electronic structure modulation induced by P vacancies and Mo doping can not only achieve thermoneutral ΔGH* for hydrogen evolution reaction but also enhance dehydrogenation kinetics from *N2H4 to *NHNH2 for HzOR, achieving enhanced dehydrogenation kinetics.

Modulating electronic structure of interfacial Fe sites in Fe2N/CoFe2O4 nano-heterostructure for enhancing corrosion-resistance and oxygen electrocatalysis in zinc-air battery

Interface engineering can regulate electronic structure of transition-metal nitrides to promote their electrocatalytic activities. However, design of iron nitride (Fe2N)-based electrocatalytic interface with desirable properties is still challenging. Here, an in-situ nucleation strategy is developed to construct the highly-dispersed Fe2N/spinal (CoFe2O4) heterojunctions to optimize the electro-conductivity and activity. The heterostructure exhibits robust activities towards ORR (half-wave potential, 0.903 V) and OER (overpotential, 300 mV). Interfacial interactions between Fe2N and CoFe2O4 mitigate the corrosion (leaching) and severe agglomeration of active components in harsh environments to stabilize the electrocatalytic activity, maintaining the integrity of heterostructure and the sustainable exposure of active sites. Theorical calculations confirm the feasibility of incorporating Fe2N into basal plane of spinal lattice (Fe2N (002) and CoFe2O4 (400) is well matched). Modulated electronic state optimizes the adsorption/desorption strength of O-intermediates on the interfacial Fe-sites (the main active sites) of Fe2N/CoFe2O4 for both ORR and OER. Strong coupling of Fe2N and CoFe2O4 bolsters the charge-transfer across the interfaces to substantially accelerate the ORR/OER kinetics. Notably, by vital of a small potential-gap (0.634 V), it displays excellent power-density (225 mW cm−2) and cycling-stability (280 h) in zinc-air battery. This work enriches the understanding of electronic structure modulation of hetero-structured nitride/spinel-based electrocatalysts.

Highly-Exposed Co-CoO Derived from Nanosized ZIF-67 on N-Doped Porous Carbon Foam as Efficient Electrocatalyst for Zinc-Air Battery.

Non-precious-metal based electrocatalysts with highly-exposed and well-dispersed active sites are crucially needed to achieve superior electrocatalytic performance for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) toward zinc-air battery (ZAB). Herein, Co-CoO heterostructures derived from nanosized ZIF-67 are densely-exposed and strongly-immobilized onto N-doped porous carbon foam (NPCF) through a self-sacrificial pyrolysis strategy. Benefited from the high exposure of Co-CoO heterostructures and the favorable mass and electron transfer ability of NPCF, the Co-CoO/NPCF electrocatalyst exhibits remarkable performance for both ORR (E1/2 =0.843V vs RHE) and OER (Ej=10mAcm-2 =1.586V vs RHE). Further application of Co-CoO/NPCF as the air-cathode in rechargeable ZAB achieves superior performance for liquid-state ZAB (214.1mWcm-2 and 600 cycles) and flexible all-solid-state ZAB (93.1mWcm-2 and 140 cycles). Results from DFT calculations demonstrate that the electronic metal-support interactions between Co-CoO and NPCF via abundant C-Nx sites is favorable for electronic structure modulation, accounting for the remarkable performance.

Local Electronic Structure Modulation Enables Fast‐Charging Capability for Li‐Rich Mn‐Based Oxides Cathodes With Reversible Anionic Redox Activity

AbstractAnionic and cationic redox chemistries boost ultrahigh specific capacities of Li‐rich Mn‐based oxides cathodes (LRMO). However, irreversible oxygen evolution and sluggish kinetics result in continuous capacity decay and poor rate performance, restricting the commercial fast‐charging cathodes application for lithium ion batteries. Herein, the local electronic structure of LRMO is appropriately modulated to alleviate oxygen release, enhance anionic redox reversibility, and facilitate Li+ diffusion via facile surface defect engineering. Concretely, oxygen vacancies integrated on the surface of LRMO reduce the density of states of O 2p band and trigger much delocalized electrons to distribute around the transition metal, resulting in less oxygen release, enhancing reversible anionic redox and the MnO6 octahedral distortion. Besides, partially reduced Mn and lattice vacancies synchronously stimulate the electrochemical activity and boost the electronic conductivity, Li+ diffusion rate, and fast charge transfer. Therefore, the modified LRMO exhibits enhanced cyclic stability and fast‐charging capability: a high discharging capacity of 212.6 mAh·g−1 with 86.98% capacity retention after 100 cycles at 1 C is obtained and to charge to its 80%, SOC is shortened to 9.4 min at 5 C charging rate. This work will draw attention to boosting the fast‐charging capability of LRMO via the local electronic structure modulation.

Flexible organic-intercalated WSe2 hybrid: electronic structure modification and thermoelectric performance optimization

Two-dimensional tungsten selenide (WSe2) has great potential in thermoelectric (TE) applications, but dimensionality reduction results in a dramatic increase in thermal conductivity, which is not beneficial for improving thermoelectric performance. In this work, an electrochemical intercalation method is utilized to fabricate an organic-inorganic hybrid superlattice structure by decoupling the WSe2 layers without damaging the original bulk structure and then intercalating tetrabutylammonium (TBA) cations into the inorganic layers. The few-layer mixed-staging TBA-WSe2 hybrid with alternating stacking organic TBA cations and WSe2 inorganic layers possesses an electronic structure similar to that of the few-layer WSe2, which is beneficial for an enhanced Seebeck coefficient. The electron injection results in a considerable increase in the carrier concentration while the disorder in the mixed-staging structure succeeds in improving phonon scattering, leading to an enhanced figure-of-merit ZT of 0.25 at 340 K, which is three orders of magnitude higher than that of the pristine WSe2 single crystal and one of the highest ZT values among WSe2-based thermoelectric materials in recent years. This work may guide future research on dimensionality reduction in the electronic structures of bulk materials and the fabrication of flexible superlattice hybrids with considerable TE performance.

Selective hydroxyl generation for efficient pollutant degradation by electronic structure modulation at Fe sites

Hydrogen peroxide (H2O2) is an important green oxidant in the field of sewage treatment, and how to improve its activation efficiency and generate free radicals with stronger oxidation performance is a key issue in current research. Herein, we synthesized a Cu-doped α-Fe2O3 catalyst (7% Cu-Fe2O3) for activation of H2O2 under visible light for degradation of organic pollutants. The introduction of a Cu dopant changed the d-band center of Fe closer to the Fermi level, which enhanced the adsorption and activation of the Fe site for H2O2, and the cleavage pathway of H2O2 changed from heterolytic cleavage to homolytic cleavage, thereby improving the selectivity of •OH generation. In addition, Cu doping also promoted the light absorption ability of α-Fe2O3 and the separation of hole-electron pairs, which enhanced its photocatalytic activities. Benefiting from the high selectivity of •OH, 7% Cu-Fe2O3 exhibited efficient degradation activities against ciprofloxacin, the degradation rate was 3.6 times as much as that of α-Fe2O3, and it had good degradation efficiency for a variety of organic pollutants.

Facilitating Reconstruction of the Heterointerface Electronic Structure by the Enriched Oxygen Vacancy for the Oxygen Evolution Reaction

Exploring high-performance non-precious metal-based electrocatalysts for the sluggish oxygen evolution reaction (OER) process is fundamentally significant for the development of multifarious renewable energy conversion and storage systems. Oxygen vacancy (Vo) engineering is an effective leverage to boost the intrinsic activity of OER, but the underlying catalytic mechanism remains anfractuous. Herein, we realize the construction of oxygen vacancy-enriched porous NiO/ln2O3 nanofibers (designated as Vo-NiO/ln2O3@NFs hereafter) via a facile fabrication strategy for efficient oxygen evolution electrocatalysis. Theoretical calculations and experimental results uncover that, compared with the no-plasma engraving component, the presence of abundant oxygen vacancies in the Vo-NiO/ln2O3@NFs is conducive to modulating the electronic configuration of the catalyst, altering the adsorption of intermediates to reduce the OER overpotential and promote O* formation, upshifting the d band center of metal centers near the Fermi level (Ef), and also increasing the electrical conductivity and enhancing the OER reaction kinetics simultaneously. In situ Raman spectra proclaim that the oxygen vacancy can render the NiO/ln2O3 more easily reconstructible on the surface during the OER course. Therefore, the as-obtained Vo-NiO/ln2O3@NFs demonstrated distinguished OER activity, with an overpotential of only 230 mV at 10 mA cm-2 and excellent stability in alkaline medium, surmounting the majority of the previously reported representative non-noble metal-based candidates. The fundamental insights gained from this work can pave a new path for the electronic structure modulation of efficient, inexpensive OER catalysts via Vo engineering.

Atomic hydrogen storage in ternary InPd2Cu – electronic structure and chemical bonding approach: A DFT study

The crystal structure of the recently discovered ternaryordered intermetallic compound InPd2Cu was observed from a different perspective. Hydrogen insertion into the face-sharing perfect tetrahedral sites (the 16m site) was fundamentally investigated by exploring the energetics of several possible hydrogenated configurations by applying first-principle density functional theory calculations. The maximum possible H-atom intake capacity would be in the range of ∼4H/formula unit. The modification of electronic structure, metal–H bonding interactions, and electronic redistribution after hydrogenation was investigated by the density of states, crystal orbital Hamilton population, and Mulliken population analysis respectively.

Boosting photocatalysis of hydrazone-linked covalent organic frameworks through introducing electron-rich conjugated aldehyde

Hydrazone-linked COFs have shown promising potential in photocatalysis, but still face problems of limited visible-lightabsorption and inefficient photocarrier separation/transportation. Herein, electron-rich and conjugated benzotrithiophene (BTT) is introduced into the aldehyde monomer to get two novel BTT-based hydrazone-linked COFs (BTT-Hz-1, −2). Systematical experiments and theoretical calculations show that comparing with the benzene aldehyde-based COFs (TFB-Hz-1, −2), conjugated structure of BTT broadens the visible-light absorption range and improves the transfer efficiency of the photocarriers; electron-rich structure of BTT constructs strong built-in electric field within the COFs, therefore promotes theseparationofphotocarriers. As a result, BTT-Hz-1 shows a recorded photocatalytic H2 evolution rate for hydrazone-linked COFs of 17.27 mmol g-1h−1, 22 times than that of TFB-Hz-1, and also reveals noble metal-free CO2 photoreduction property with CO evolution rate of 774.3 μmol g-1h−1. This work presents the importance of electronic structure modulation to the COF-based photocatalysis, and opens a new avenue to improve the photocatalysis performance of hydrazone-linked COFs.

Tailoring Electronic Structure to Achieve Maximum Utilization of Transition Metal Redox for High-Entropy Na Layered Oxide Cathodes.

Charge compensation from cationic and anionic redox couples accompanying Na+ (de)intercalation in layered oxide cathodes contributes to high specific capacity. However, the engagement level of different redox couples remains unclear and their relationship with Na+ content is less studied. Here we discover that it is possible to take full advantage of the high-voltage transition metal (TM) redox reaction through low-valence cation substitution to tailor the electronic structure, which involves an increased ratio of Na+ content to available charge transfer number of TMs. Taking NaxCu0.11Ni0.11Fe0.3Mn0.48O2 as the example, the Li+ substitution increases the ratio to facilitate the high-voltage TM redox activity, and further F-ion substitution decreases the covalency of the TM-O bond to relieve structural changes. As a consequence, the final high-entropy Na0.95Li0.07Cu0.11Ni0.11Fe0.3Mn0.41O1.97F0.03 cathode demonstrates ∼29% capacity increase contributed by the high-voltage TMs and exhibits excellent long-term cycling stability due to the improved structural reversibility. This work provides a paradigm for the design of high-energy-density electrodes by simultaneous electronic and crystal structure modulation.

Interfacial electronic structure modulated magnetic properties in Ta/CoFeB/Ta multilayers

Thinfilm heterostructure Ta/CoFeB/TaOx can exhibit chiral magnetic textures such as skyrmions as well as spin-orbit torque induced zero field magnetization switching, which offers great promise for next-generation information storage technologies. Here, we provide a strong correlation between the structural and magnetic properties in as-deposited and annealed Ta (1 nm)/ CoFeB (1.5 nm)/ TaOx (1 nm) trilayer and Ta (1 nm)/ CoFeB (1.5 nm)/ Ta (t)/ CoFeB (1.5 nm)/ TaOx (1 nm)] multilayered stack with t = 0.5, 1 nm. Interestingly, x-ray reflectivity results indicate improvement in the interface quality post annealing up to 300 °C. While the thinner Ta spacer layer (0.5 nm) in the stack causes the formation of smaller interface width, the thicker Ta spacer (1 nm) results in relatively larger interface width. Annealing results in the enhancement of saturation magnetization (Ms) and uniaxial magnetic anisotropy (UMA) and the extent of variation is mostly determined by thickness of the spacer Ta layer. Magneto-optical Kerr effect measurement suggests the existence of strong two-fold UMA in the film stack with Ta spacer layer 0.5 nm, however, its strength diminishes as the Ta spacer layer thickness is increased to 1.0 nm. Furthermore, the in-depth chemical/electronic investigations using x-ray photoelectron spectroscopy technique reveal the formation of additional chemical states such as TaB and TaOB at the interfaces. Remarkably, Boron diffusion and likely oxygen migration from the Fe-oxide/Co-oxide in CoFeB to neighboring Ta layers improves the metallic nature of Fe and Co due to annealing. Note that the thicker Ta spacer has a significant impact on the chemical transformation at the interface in comparison to that of thinner Ta spacer layer. Overall, in these Ta/CoFeB multilayered stacks, the thickness of the Ta spacer layer and annealing temperature play a crucial role in controlling interface quality that eventually governs the magnetic characteristics. These results provide new insight into the interfacial electronic structure modifications which are essential for controlling DMI and stabilization of skyrmions in Ta/CoFeB multilayers for future spintronic device applications.

The identification of dual active routes for highly efficient furfural oxidation reaction coupling with hydrogen production over Re modulated Co(OH)2/CC

It is of great significance and challenge to tune the active sites of two-dimensional materials and identify the exclusive active sites for separate reaction toward hydrogen evolution reaction (HER) coupled with electrochemical oxidation (ECO) reaction. Herein, Re was introduced to tune d band charge density of Co, which reduced the energy barrier of water splitting for HER. Meanwhile, the abundant oxygen vacancies (Ov) caused by Re introduction resulted in a new reaction route for furfural oxidation reaction (FOR). That is, the adsorbed OH− on Ov accelerates the dehydrogenation of Co(OH)O, and the active site further promotes the nucleophile dehydrogenation, thus improving the catalytic performance of FOR. In conclusion, Re-Co(OH)2/CC with Re modified Co-centered sites displays dual active routes, which simultaneously enhance FOR and HER with a cell voltage (1.36 V) at 10 mA cm−2, surpassing the most two-dimensional transition-metal hydroxides (2D TMHs) results reported as we known. This work provides new insights into the modulation of Co electronic structure and Ov concentration, which results in enhanced bifunctional electrocatalytic reactions.

Defective Metal Oxides: Lessons from CO2 RR and Applications in NOx RR.

Sluggish reaction kinetics and the undesired side reactions (hydrogen evolution reaction and self-reduction) are the main bottlenecks of electrochemical conversion reactions, such as the carbon dioxide and nitrate reduction reactions (CO2 RR and NO3 RR). To date, conventional strategies to overcome these challenges involve electronic structure modification and modulationof thecharge-transfer behavior. Nonetheless, key aspects of surface modification, focused on boosting the intrinsic activity of active sites on the catalyst surface, are yet to be fully understood. Engingeering of oxygen vacancies (OVs) can tune surface/bulk electronic structure and improve surface active sites of electrocatalysts. The continuous breakthroughs and significant progress in the last decade position engineering of OVs as a potential technique for advancing electrocatalysis. Motivated by this, the state-of-the-art findings of the roles of OVs in both the CO2 RR and the NO3 RR are presented. The review starts with a description of approaches to constructing and techniques for characterizing OVs. This is followed by an overview of the mechanistic understanding of the CO2 RR and a detailed discussion on the roles of OVs in the CO2 RR. Then, insights into the NO3 RR mechanism and the potential of OVs on NO3 RR based on early findings arehighlighted. Finally, the challenges in designing CO2 RR/NO3 RR electrocatalysts and perspectives in studying OV engineering are provided.

A Mo doping WO3/CdZnS heterojunction photoelectrode for boosting electron storage capacity

Most of the photoelectrodes for photoelectrochemical cathodic protection (PECCP) technology reported at present cannot store electrons, leading to the inability to protect metals in the absence of light, which becomes the main defect that limits the practical application of PECCP. In this work, a Mo doping WO3/CdZnS heterojunction photoelectrode with electrons storage capability was prepared, by which the PECCP can be kept running in the absence of light. The result of theoretical calculation of density functional validates that Mo doping can introduce new doping levels into WO3, leading to modifications in the intrinsic electronic structure associated with increasing capacitance and conductivity. The compounding of CdZnS can not only broaden the light absorption threshold of the photoelectrode, but also charge the Mo-WO3. Besides, the construction of heterojunction also facilitates the oriented separation and migration of photogenerated carriers. The 0.3%Mo-WO3/CdZnS-2 composite photoelectrode with desirable capacity of electron storage can store the quantity of electric charge about 1.87 × 10−3 C after 100 s illumination, which is about 1.5 times of WO3/CdZnS-2 without Mo doping. In the meanwhile, the persistent PECCP performance in the absence of light was also prolonged from 481 s to 584 s.

Identifying the in situ protection role of MnO2 nanosheets on Co oxide for superior water oxidation

As a limiting step of electrochemical water splitting, the oxygen evolution reaction calls for efficient catalysts to surmount the high energy barrier. In this work, the synthesis of O-deficient Co3O4 nanoparticles with abundant surface area was realized by applying two-dimensional MnO2 nanosheets as a self-protection agent. The strong interaction between Mn and Co was confirmed by our experiments and DFT calculations that the valence state is increased for Co while it is reduced for Mn during the annealing in reducing atmosphere. Mn3+δ with stronger Lewis acidity can protect Co2+ from being reduced when subjected to the H2 treatment. The H2– reduced CoMn oxide under 300 °C (CMO-H300) shows the best OER activity with an overpotential of 280 mV in 1 M KOH and 460 mV in 1 M phosphate buffer (PBS) at 10 mA cm-2 geo, which can be attributed to the optimal chemical state, appropriate oxygen vacancies and highly exposed surface area. Operando Raman spectroscopy combined with ex-situ XPS revealed the manner of active species evolution in CMO-FD (Freezing-drying CoMn oxide) and CMO-H300 under the OER process, which accounted for the dynamic change of chronoamperometry. Our findings provide a different viewpoint for novel electrocatalyst fabrication by introducing a self-sacrifice agent that in situ promotes electronic structure modulation and high surface area preservation.

Elucidating the promotion mechanism of the ternary cooperative heterostructure toward industrial-level urea oxidation catalysis

From the perspective of electronic structure modulation, it is highly desirable to rationally design the active urea oxidation reaction (UOR) catalysts through interface engineering. The binary cooperative heterostructure systems have been shown significant enhancement for catalyzing UOR, but their performance still remains unsatisfactory for industrialization because of the unfavorable intermediate adsorption/desorption and deficient electron transfer channels. In response, taking the ternary cooperative Ni5P4/NiSe2/Ni3Se4 heterostructure as the proof-of-concept paradigm, a catalytic model is rationally put forward to elucidate the UOR promotion mechanism at the molecular level. The rod-like Ni5P4/NiSe2/Ni3Se4 nanoarrays with three-phase heterojunction are experimentally fabricated on Ni foam (named as Ni5P4/NiSe2/Ni3Se4/NF) via simple two-step processes. The density functional theory (DFT) calculations disclose that construction of Ni5P4/NiSe2/Ni3Se4 heterostructure model not only induce charge redistribution at the interfacial region for creating innumerable electron transfer channels, but also endow it with a moderate d-band center that could help to build a balance between adsorption and desorption of diverse UOR intermediates. Benefiting from the unique rod-like nanoarrays with large specific surface area and the optimized electronic structure, the well-designed Ni5P4/NiSe2/Ni3Se4/NF could act as a robust catalyst for driving UOR at industrial-level current densities under tough environments, offering great potential for commercial applications.

Dual Atoms (Fe, F) Co-Doping Inducing Electronic Structure Modulation of NiO Hollow Flower-Spheres for Enhanced Oxygen Evolution/Sulfion Oxidation Reaction Performance.

Heteroatoms Fe, F co-doped NiO hollow spheres (Fe, F-NiO) are designed, which simultaneously integrate promoted thermodynamics by electronic structure modulation with boosted reaction kinetics by nano-architectonics. Benefiting from the electronic structure co-regulation of Ni sites by introducing Fe and F atoms in NiO , as the rate-determined step (RDS), the Gibbs free energy of OH* intermediates (ΔGOH* ) for Fe, F-NiO catalyst is significantly decreased to 1.87eV for oxygen evolution reaction (OER) compared with pristine NiO (2.23eV), which reduces the energy barrier and improves the reaction activity. Besides, densities of states (DOS) result verifies the bandgap of Fe, F-NiO(100) is significantly decreased compared with pristine NiO(100), which is beneficial to promote electrons transfer efficiency in electrochemical system. Profiting by the synergistic effect, the Fe, F-NiO hollow spheres only require the overpotential of 215mV for OER at 10mA cm-2 and extraordinary durability under alkaline condition. The assembled Fe, F-NiO||Fe-Ni2 P system only needs 1.51V to reach 10mA cm-2 , also exhibits outstanding electrocatalytic durability for continuous operation. More importantly, replacing the sluggish OER by advanced sulfion oxidation reaction (SOR) not only can realize the energy saving H2 production and toxic substances degradation, but also bring additional economic benefits.