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A highly active cactus-like Fe2O3/C@NCNT micro-nano-structure was firstly fabricated by a metal-catalyzed graphitization-nitridization driven tip-growth process and air oxidation induced Kirkendall effect, which showed an extraordinary electrochemical performance in LIBs.

Metal oxide nanoparticles encapsulated and nitrogen-doped carbon nanotubes was prepared by a novel low-temperature metal-catalyzed synthesis strategy from carbon nitride as anodic materials of high-performance lithium-ion batteries.

A self-powered energy system was constructed by integrating a silicon solar cell, zinc–air batteries and a water splitting device to achieve uninterrupted H2 generation, based on Co0.85Se/NC catalysts with promising OER, ORR and HER performance.

Benefiting from the excellent tri-functional ORR, OER, and HER performance of FeNiP@p-NPCF/CC, the integrated electrolyzer, powered by solar cell in day and aqueous zinc–air battery in night, achieves uninterruptible H2 production.

Heterostructure engineering of electrocatalysts provides a fascinating platform to reasonably manipulate the physicochemical properties of nanomaterials and further improve their catalytic efficiency for water electrolysis. However, it still remains a huge challenge to construct well-designed core-shell heterostructured catalysts and identify the key role of components for synergistic catalysis. Herein, a melted polymeric salt tactics was innovatively developed to synthesize heterostructured Ni@Ni(OH)2 core-shell nanomaterials supported on porous carbon (named Ni@Ni(OH)2/PC), wherein well-defined Ni(OH)2-Ni heterostructure plays a pivotal role in improving electrocatalytic activity for water reduction and oxidation. Besides, the stable porous carbon support functions as a highway for continuous electron transfer between Ni and Ni(OH)2, and simultaneously enables the full exposure of accessible active sites. The fabricated Ni@Ni(OH)2/PC exhibits outstanding bifunctional electrocatalytic performance for overall water splitting (ƞ10 = 1.55 V) with a good long-time stability. This work sheds new light on the design of engineering heterostructure of active bifunctional electrocatalysts for efficient energy conversion system.

Embedding metal species into zeolite frameworks can create framework-bond metal sites in a confined microenvironment. The metals sitting in the specific T sites of zeolites and their crystalline surroundings are both committed to the interaction with the reactant, participation in the activation, and transient state achievement during the whole catalytic process. Herein, we construct isolated Co-motifs into purely siliceous MFI zeolite frameworks (Co-MFI) and reveal the location and microenvironment of the isolated Co active center in the MFI zeolite framework particularly beneficial for propane dehydrogenation (PDH). The isolated Co-motif with the distorted tetrahedral structure ({(≡SiO)

Photocatalysts with highly efficient charge separation are of critical significance for improving photocatalytic hydrogen production performance. Herein, a cost-effective and high-performance composite photocatalyst, cobalt-phosphonate-derived defect-rich cobalt pyrophosphate hybrids (CoPPi-M) modified Cd0.5Zn0.5S is rationally devised via defect and interface engineering, in which the co-catalyst CoPPi-M delivers a strong interaction with host photocatalyst Cd0.5Zn0.5S, rendering Cd0.5Zn0.5S/CoPPi-M with a remarkably improved efficiency of charge separation and migration. Besides, Cd0.5Zn0.5S/CoPPi-M exhibits a hydrophilic surface with ample access to electrons and a strong reduction ability of electrons. Benefiting from these advantages, the integration of defect-rich cobalt pyrophosphate and Cd0.5Zn0.5S enables Cd0.5Zn0.5S/CoPPi-M−5% with high photocatalytic H2 production rate of 6.87 mmol g−1h−1, which is 2.46 times higher than that of pristine Cd0.5Zn0.5S, and the notable apparent quantum efficiency (AQE) is 20.7% at 420 nm. This work provides a promising route for promoting the photocatalytic performance of non-precious hybrid photocatalyst via defect and interface engineering, and advances energy-generation and environment-restoration devices.

Ni2P@CN is employed to construct a novel Cd0.5Zn0.5S/Ni2P@CN composite photocatalyst which guarantees highly efficient interfacial charge separation and transfer between Ni2P@CN and Cd0.5Zn0.5S, resulting in enhanced photocatalytic activity.

Synergistic electrocatalysis between nonstoichiometric Cu2−xSe and Cu2Se berzelianite for highly efficient hydrazine-assisted water splitting.

Fe-based oxides are considered as promising anode materials for lithium-ion batteries (LIBs) due to their high theoretical capacities, low cost, natural abundance and environmental friendliness.

Photocatalytic, photoelectrochemical and electrocatalytic water splitting provides advanced approaches to produce green hydrogen as sustainable and renewable energy carrier. The development of highly efficient catalysts is the key to achieve cost-effective and large-scale production of hydrogen. Recently, P-containing catalysts have gained a great deal of attention owing to their diverse chemical valence states, tunable structure and unique physicochemical properties. In this review, an overview of up-to-date progress in water splitting of P-containing photo- and electro-catalysts including elemental P, transition metal phosphides, metal phosphates/phosphonates and metal phosphorus trichalcogenides is provided. The general introduction to the water splitting mechanism and the activity origin of P-containing catalysts are briefly presented to provide rational guidance for the design of highly efficient catalysts. Notably, the innovational strategies to design P-containing catalysts with enhanced photocatalytic and electrocatalytic water splitting activity are summarized with respect to modifying phase, introducing foreign element, tailoring morphology and engineering interface. In each section, we aim to deeply clarify the theory-structure-property relationship and provide underlying reasons behind enhanced catalytic performance. Finally, some challenges and research orientations of P-containing catalysts toward photo-/electro-catalytic water splitting are proposed from the perspectives of practical application and mechanism investigation.

In comparison to pure water, seawater is widely accepted as an unlimited resource. The direct seawater splitting is economical and eco-friendly, but the key challenges in seawater, especially the chlorine-related competing reactions at the anode, seriously hamper its practical application. The development of earth-abundant electrocatalysts toward direct seawater splitting has emerged as a promising strategy. Highly efficient electrocatalysts with improved selectivity and stability are of significance in preventing the interference of side reactions and resisting various impurities. This review first discusses the macroscopic understanding of direct seawater electrolysis and then focuses on the strategies for rational design of electrocatalysts toward direct seawater splitting. The perspectives of improved electrocatalysts to solve emerging challenges and further development of direct seawater splitting are also provided.

Electrocatalytic water splitting using power generated from renewable energy to produce hydrogen has been considered as one of the more attractive approach to alleviate the problems of energy crisis and environmental pollution. One of the biggest challenges for the large-scale application of water electrolysis is the searching of the low cost electrocatalysts with high and stable activity toward both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The well-developed porous features of materials synthesized from the earth abundant elements endow them with the enhanced mass transfer and improved electronic interconnection during electrochemical reactions, resulting in the excellent electrocatalytic performance for both OER and HER. Herein, this review focuses on the recent development of innovation strategies for the fabrication of porous non-noble-metal materials including heteroatom-doped carbon-based and transition metal (mainly Co, Ni, and Fe)-based materials as efficient electrocatalysts for overall water splitting. Specially, a detailed discussion of the structure–activity correlation gives an insight on the origin of the high electrocatalytic performance of porous materials obtained from different strategies, and provides guidance for future design and preparation of highly efficient electocatalysts based on non-precious carbon or metal materials for overall water splitting.

Highly efficient and ultrastable nonprecious metal-based electrocatalysts are promising alternatives to platinum (Pt)-based catalysts in electrocatalyzing oxygen reduction reaction (ORR) process. In the present work, nitrogen and sulfur dual-doped hierarchically porous carbon with trapped Mn species (MnNSC-950) was fabricated, which integrates the modulation of the electronic structure for boosted intrinsic activity with the engineering of hierarchical porosity for enriched active sites. The MnNSC-950 shows a positive onset potential of 0.95 V and a large limiting current density of 5.4 mA cm−2, which can rival that of the commercial Pt/C catalyst in 0.1 M KOH, together with a robust long-term stability. Moreover, the MnNSC-950 as ORR catalyst in Zn-air battery achieves a high power density of 107 mW cm−2 and robust cycling performance over 150 h, exceeding that driven by Pt/C cathode. The excellent electrochemical performance is also shown in both neutral and acidic media. This work provides an enabling route to prepare non-noble metal-based catalysts featuring well-engineered geometric and component peculiarities for practical application of energy conversion systems.

The practical application of photocatalytic water splitting for hydrogen evolution hinges on the development of high-efficient and low-cost photocatalysts. Defects engineering has emerged as a promising strategy to enhance photocatalytic activity effectively. Herein, a facile and versatile co-precipitation method is proposed to fabricate mesoporous Cd-Zn-S solid solutions (E-CdxZn1-xS) with abundant surface defects by the inorganic salts formed in the reaction system as self-template. Compared with Cd-Zn-S solid solutions (W-Cd0.65Zn0.35S) prepared by the traditional co-precipitation method, the enhanced specific surface area and abundant surface defects endow E-Cd0.65Zn0.35S with more accessible active sites and effective separation of electron-hole pairs for the photocatalytic water splitting reaction. The E-Cd0.65Zn0.35S solid solution exhibits hydrogen evolution rate of 5.2 mmol h−1 g−1 without loading noble metal as cocatalyst under visible light, which is 1.13 times higher than that of W-Cd0.65Zn0.35S sample. The present work provides a simple, low-cost and prospective strategy for the synthesis of defective Cd-Zn-S solid solutions, and it also delivers guidance to design and develop the advanced visible-light photocatalyst in the future.

It is of vital importance to accelerate the sluggish oxygen reduction reaction (ORR) process at the cathode with earth-abundant metal-based catalysts for the commercialization of low-temperature polymer electrolyte membrane fuel cells. In consideration of high catalytic activity, long-term stability and low cost of potential ORR electrocatalysts, transition metal species have attracted much interest and transition metal-nitrogen-carbon (M−N/C, M = Fe, Co, Ni, Mn, etc.) catalysts have been widely considered as the most promising non-precious metal catalysts for ORR. Herein, the fundamental understanding of ORR catalytic mechanism and the identification of active centers are briefly introduced, and then different M−N/C catalysts classified by precursors with the strategies for design and optimization are highlighted. The challenges and possible opportunity for future development of high-performance ORR catalysts are finally proposed.

The electrochemical production of green and low-cost ammonia requests the development of high-performance electrocatalysts. In this work, the ampoule method was applied to modulate the surface of the zinc electrode by implanting defects and low-valent active sites. The N-doped ZnS electrocatalyst was thus generated by sulfurization with thiourea and applied for electrocatalytic nitrogen reduction reaction (ENRR). Given the rich sulfur vacancies and abundant Zn-N active sites on the surface, excellent catalytic activity and selectivity were obtained, with an NH3 yield rate of 2.42 × 10–10 mol s−1 cm−2 and a Faradaic efficiency of 7.92% at − 0.6 V vs. RHE in 0.1 M KOH solution. Moreover, the as-synthesized zinc electrode exhibits high stability after five recycling tests and a 24 h potentiostatic test. The comparison with Zn foil, non-doping ZnS/Zn and recent metal sulfide electrocatalysts further demonstrated advanced catalytic performance of N@ZnS/Zn for ENRR. By simple synthesis, S vacancies, and N-doping defects, this promising electrocatalyst would represent a good addition to the arena of transition-metal-based catalysts with superior performance in ENRR. Graphic abstract