Integrating S-scheme and Schottky junctions in a 0D/2D/2D architecture is crucial for fully levering the synergy between nanostructure and interface properties. Herein, we construct 0D/2D NiS2@LaCO3OH heterostructure via combined top-down and bottom-up reconstruction of LaNiO3, then fabricate 0D/2D/2D NiS2@LaCO3OH/gC3N4 hierarchical heterostructure through mechanical mixing. The design encapsulates 0D/2D NiS2@LaCO3OH within 2D g-C3N4, enhancing light trapping and interfacial contact. Moreover, the S-scheme and Schottky coupling further facilitates charge transfer while lowering HER overpotential, significantly boosting photocatalytic efficiency. The optimized NiS2@LaCO3OH(0.5)/g-C3N4 achieves 3421.6 mu mol g- 1 h- 1 H2 evolution rate with an impressive apparent quantum yield. This study offers practical guidance for rational heterojunction design via bulk reconstruction.

Developing efficient multifunctional materials for the oxygen evolution reaction (OER) and supercapacitors has become essential for storing and converting energy. Taking advantage of the structural flexibility of metal–organic frameworks (MOFs), bifunctional electrochemical nanomaterial LaFeCoOOH with high performance is successfully synthesized by doping rare earth La atoms in transition metals. La doping modifies the coordination environment of active sites and material morphology, modulates the energy structure, improves material conductivity, and optimizes the adsorption and desorption performance of oxygen intermediates. LaFeCoOOH demonstrates exceptional electrocatalytic activity for OER, achieving a remarkably low overpotential of 177 mV at 10 mA cm −2 current density in 1 m KOH alkaline electrolyte. The material exhibits outstanding operational stability, maintaining consistent performance for over 1000 h at an elevated current density of 100 mA cm −2 under identical alkaline conditions. Furthermore, LaFeCoOOH electrode displays superior electrochemical energy storage capabilities, demonstrating an impressive specific capacitance of 3508 mF cm −2 at 1 mA cm −2 current density. When configured as an asymmetric supercapacitor (LaFeCoOOH//Activated Carbon (AC)) using 6 m KOH electrolyte, the device achieves an exceptional energy density of 118.52 µWh cm −2 while delivering a power density of 1700 µW cm −2 , highlighting its dual functionality for both energy conversion and storage applications. Hence, this study provides a new perspective for the exploration of new multifunctional transition metal composites modified with rare earth elements for energy storage and conversion applications.

Herein, a reverse bias heterojunction NiCoS/NiCo-OH with mesopores as the positive electrode was constructed by interface engineering. During the process of charging, the application of a positive bias potential by the external circuit to the reverse bias heterojunction NiCoS/NiCo-OH enhances the accumulation of charges within the NiCoS nanosheets. Under the modulation of the built-in electric field at the interface, the mesoporous interface of NiCo-OH acts as a receiver, collecting charges from NiCoS nanosheets and forming a channel leading to efficient ion diffusion and charge transfer. The specific capacity of the NiCoS/NiCo-OH electrode is up to 406.5 mA h g(-1) at 1 A g(-1). It demonstrates ultrahigh rate performance, reaching 81.9% (50 A g(-1)) and 77.4% (100 A g(-1)). The hybrid supercapacitor NiCoS/NiCo-OH//FNG shows a high energy density of 51.3 W h kg(-1) at 1650 W kg(-1). Moreover, the capacity of the Zn||NiCoS/NiCo-OH battery reaches 419.1 mA h g(cathode)(-1) at 1 A g(-1), and it can still maintain 73% (306.3 mA h g(cathode)(-1)) at 100 A g(-1).

Designing novel rare-earth-transition metal composites is at the forefront of electrocatalyst research. However, the modulation of transition metal electronic structures by rare earths to induce vacancy defects and enhance electrochemical performance has rarely been reported. In this study, we systematically investigate the mechanism by which Ce-4f electron modulation weakens the Fe-O bond, thereby altering the electronic structure in CeFevNi hydroxide to improve oxygen evolution reaction (OER) performance. Theoretical calculations and experimental characterizations reveal that Ce-4f orbitals function as electron-modulation reservoirs, capable not only of retaining or donating electrons but also of influencing the material's electronic structure. Moreover, Ce-4f bands optimize the Fe lower Hubbard bands (LHB) and O-2p bands, leading to weakened Fe-O bonds and the formation of cationic vacancies. This change results in the upshift of the d-band center at the active sites, favoring the reaction energy barrier for oxygen intermediates in the OER process. The synthesized catalyst demonstrated an overpotential of 201 mV at 10 mA cm-2 and a lifetime exceeding 200 h at 100 mA cm-2 under alkaline conditions. This work offers a proof-of-concept for the application of the mechanism of rare earth-induced transition metal vacancy defects, providing a general guideline for the design and development of novel highly efficient catalysts.

Nanoscale graphene-semiconductor composite photocatalysts with fascinating properties in the photocatalytic hydrogen evolution have inspired numerous interests in broad research fields. The architectures with efficient light response and promoting charge separation at the interface between reduced graphene oxide (RGO) and semiconductor are critical, yet synthesizing them remains a formidable challenge. Herein, the photodiode arraylike LaNiO 3 /N,P-RGO (LNO/N,P-RGO) nanoreactor was constructed using an innovative strategy of acid etchinginduced nanocutting self-assembly. Ammonium dihydrogen phosphate working as both a nitrogen phosphorus co-dopant and an acid etching reagent, cuts perovskite LaNiO 3 (LNO) nanoparticles into nanorods, which are bonded evenly on the nitrogen phosphorus co-doped reduced graphene oxide (N,P-RGO) to form an n-n semiconductor heterojunction LNO/N,P-RGO as a photodiode array-like nanoreactor via hydrothermal treatment. The photodiode array-like nanostructure exposes more active sites that are conducive to light absorption. The robust Ni-C and P-O bonds promote the narrowing of space-charge region at the interface by UV irradiation, thereby improving the transport of photogenerated carriers by visible light irradiation. The LNO/N,P-RGO nanoreactor exhibits excellent photocatalytic hydrogen evolution performance with a yield of up to 354 mu mol g-1 h-1 under UV - visible light, which is 50 times higher than that of pure perovskite LNO, and it also displays favorable recycling stability.

Transition metal sulfides are considered as potential electrode materials for high performance energy storage devices. However, structural instability during electrochemical reactions has seriously hindered their wide applications. In this study, we demonstrate that MnCo2S4/PNG (N- and P-doped graphene) composite constructed with hetero-atomic induction exhibits excellent morphological stability. Heterogeneous atoms doping on graphene can change its surface charge distribution. Under the induced effect of surface charge, the crystal growth and assembly process of MnCo2S4 nanostructure are changed as well, which leads to MnCo2S4 nanoparticles (NPs) uniformly anchored on the curled and folded PNG layer. In this case, it avoids the agglomeration of MnCo2S4 NPs, and thus increasing the specific surface area and pore volume of the composite, which is conducive to the full contact between the electrode and the electrolyte and therefore the rapid diffusion rate of the electrolyte ions at the interfaces. The obtained 1.4MnCo2S4/PNG material has a specific capacitance of 2465 F g−1 at 1 A g−1. In addition, the electrode possesses high conductivity, excellent rate performance and cyclic stability. The assembled 1.4MnCo2S4/PNG//PNG asymmetric supercapacitor yields an energy density of up to 65.1 Wh kg−1 under the power density of 800 W kg−1, showing excellent energy storage characteristics.

The paper presents a self-assembly approach to synthesize Ni3S2/N, P co-doped graphene (PNG) composite electrode materials for supercapacitors with high energy storage performance and structural stability. Innovatively, the self-assembly approach is induced via the surface charge effect utilizing a two-step hydrothermal method. The doping of nitrogen (N) and phosphorus (P) atoms regulates the surface charge distribution on graphene nanosheets. Therefore, in the synthesized Ni3S2/PNG heterostructures, Ni3S2 nanowires are interwoven into nests and uniformly attached to PNG. The design of the electrode materials with such a special structure not only supports each other to improve the stability of the materials but also facilitates the rapid diffusion of electrolyte ions. Based on the advantages of composition and structure, Ni3S2/PNG has a high specific capacitance of 1117C g-1 at a current density of 1 A/g and excellent rate performance. The asymmetric supercapacitors (ASC) assembled with Ni3S2/PNG and PNG as positive and negative materials respectively have a high energy density of 62 Wh kg- 1 at a power density of 158 W kg- 1.

Structure design of heterojunction photocatalysts is highly desirable for making full use abilities of each component and junction. Herein, we designed a one-pot in-situ top-down and bottom-up combination strategy to construct novel 0D/1D ordered NiO@La(OH)3 heterostructure derived from NiO@LaNiO3 using high-temperature hydrothermal treatment. The 0D/1D NiO@La(OH)3 heterostructure had better charge transport capability than its single component and the corresponding mechanical mixture. Furthermore, NiO@La(OH)3 and g-C3N4 self-assembled into 0D/1D/2D NiO@La(OH)3/g-C3N4 ternary hierarchical heterostructure photo-catalyst by electrostatic interaction. The synergistic effect of 0D/1D/2D architecture and ternary heterojunction boost the internal separation and interface transmission of its photocarriers. Therefore, the obtained 0D/1D/2D NiO@La(OH)3/g-C3N4 ternary photocatalyst exhibited significantly enhanced photocatalytic H2 evolution ac-tivity, comparable to related g-C3N4-based photocatalysts. This work enriches our insight into designing novel hierarchical heterostructure catalysts.

Interfacial electron transfer plays an important role in the boosting photoactivity of heterojunction under sunlight irradiation. Here, the lattice oxygen migration etching Agdoped perovskite induced self-assembly ternary heterojunction 0D/2D/1D Ag@Ni(OH)2/ La(OH)3 via hydrothermal treatment. The LaNiO3 controlled self-assembled into Ni(OH)2/ La(OH)3 heterojunctions at the interface and constructed a semi-coherent interface. Furthermore, it became reinforced quaternary heterojunction 0D/2D/1D/2D Ag@Ni(OH)2/ La(OH)3/g-C3N4 by electrostatic self-assembly with g-C3N4. The novel constructed Z scheme heterojunction Ag@Ni(OH)2/La(OH)3/g-C3N4 promotes the effective separation of photogenerated carriers. The semi-coherent interface between Ni(OH)2/La(OH)3 promotes the transfer of photogenerated carriers. At the same time, the silver nanoparticles on Ni(OH)2 nanosheets act as electron trapping sites to further improve the photocatalytic performance. In this way, the synthesized photoexcited quaternary heterojunction Ag@Ni(OH)2/La(OH)3/g-C3N4 showed an outstanding hydrogen production rate from photocatalytic water splitting (the yield of hydrogen was 1633 mmol/g/h) under simulated sunlight. It is comparable to many g-C3N4-based photocatalysts known at present. (c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Interface engineering as an effective material modification method can regulate local corresponding interfacial geometry and electronic structures, thus enabling a higher intrinsic activity for the oxygen evolution reaction (OER). Herein, we carefully designed p-p heterojunction precursor Co4-MOF@La(HCO2)(3) with internal electric field through electrostatic adherence, which then in-situ transformed into p-p type heterojunction electrocatalyst (Co(OH)(2))4@La(OH)(3) under KOH activation strategy. The one-step in-situ conversion of (Co(OH)2)4@La(OH)3 generated the interface with significant difference in metal atomic radius and exhibits fascinating nanostructures, which enhances the specific surface area and increases the number of active sites compared with the parent material. Impressively, the obtained material (Co(OH)(2))4@La(OH)(3) demonstrates satisfying electrocatalytic activity in OER with a low overpotential of only 233 mV to reach a current density of 20 mA cm(-2), and excellent stability for 50 h at 10 mA cm(-2) in alkaline medium. In-situ Raman technique indicates that multivalent Co centers are the true active sites during the OER process. Based on density functional theory (DFT) calculation results, La atoms possess empty d orbitals, which are beneficial to facilitate charge transfer from Co to La at the heterojunction interface. Meanwhile, the introduction of La atoms changes the coordinated environment around the adjacent atoms at the interface, which induces the upshift of the d-band center for Co atoms and increases the binding strength of the adsorbed oxygen intermediate.

g-C3N4 has attracted much attention in the field of photocatalysis. However, its high carrier recombination rate has always been an obstacle in practical application. g-C3N4-based heterostructures with an intimate interface contact is considered to be an effective solution to improve the separation and transmission of photogenerated carriers. Herein, an oxygen vacancy-mediated direct solid phase integration strategy is proposed to synthesize a 0D/2D/2D LaNiO3/RGO/g-C3N4 S-scheme heterostructure with interface chemical bonds. The optimized LaNiO3/RGO/g-C3N4 sample showed excellent hydrogen evolution rate of 1375 mu mol/g/h, which is far superior to those of pristine g-C3N4 (46 mu mol/g/h), LaNiO3/g-C3N4 (143 mu mol/g/h), RGO/g-C3N4 (307 mu mol/g/h) and mechanically mixed sample LaNiO3-RGO-g-C3N4 (625 mu mol/g/h). Also, it is comparable to many g-C3N4-based heterojunction photocatalysts known at present. The improved performance can be attributed to interfacial charge transfer promoted by interfacial chemical bonds served as charge transfer channels and the high redox capacity of S-scheme charge transfer. This work opens up a new avenue for the predictive design of reinforced heterojunction with enhanced photocatalytic performance.

Ammonium dihydrogen phosphate (NH4H2PO4) was used as an activator and co-dopant to induce the synthesis of N, P co-doped porous carbon nanosheets (NPCNs) from pomelo peel for using as high-performance supercapacitors. Pomelo peel has a unique sponge-like structure in which NH4H2PO4 particles can be evenly embedded. The pore structure and heteroatomic doping amount of NPCNs were controlled by adjusting the pyrolysis temperature. As a result, the optimal sample exhibits high specific capacitance (314 +/- 2.6 F g(-1)) and rate capability (82% of capacitance retention at 20 A g(-1)). NPCNs750 was further employed in a symmetrical supercapacitor (NPCNs-750//NPCNs-750 SSC) with 2 M Li2SO4 electrolyte, and exhibits a high energy density of 36 +/- 1.5 W h kg(-1) at a power density of 1000 W kg(-1), with excellent cycling stability with 99% retention after 10,000 cycles. A series of excellent results show that this pollution-free and cost-effective method can be used for the design and preparation of high-performance supercapacitor electrode materials. (C) 2021 Elsevier Inc. All rights reserved.

Herein, we proposed a facile method to synthesize N doped carbon quantum dots (NCQDs) using g-C3N4 as carbon-nitrogen source, and the NCQDs-modified CdS nanocomposite catalysts for photocatalytic water splitting were synthesized by one-step hydrothermal method. The results showed that the NCQDs with a size of 3.2 nm obtained by hydrothermal etching were adsorbed on the surface of CdS particles with a size of 80 nm and induced the regulation of the surface morphology of CdS particles. There was strong interaction between NCQDs and CdS through C-S bond. The introduction of NCQDs in composite catalysts not only increased the photo absorption performance but also suppressed the recombination of photo-generated carriers, which enabled the photo-generated electrons to transfer to NCQDs effectively and quickly and improved the photocatalytic performance of hydrogen production from water splitting. The composite photocatalysts showed good response to visible light in UV-Vis DRS and the photocatalytic water splitting experiment showed that the photocatalytic hydrogen production activity of composite catalysts was significantly improved under visible light (lambda > 400 nm). And the maximum hydrogen production rate reached 2306.1 mu mol/g/h, which was about 7 times the amount of unsupported NCQDs sample.

The nickel-cobalt double hydroxide hybrid materials induced by biomass-derived carbon quantum dots (CQDs) have a three-dimensional network structure of cross-linked nanorods. The results demonstrate that the functional groups on the CQDs derived from pomelo peel promoted the nucleation and confined the growth of nickel-cobalt double hydroxide. The as-synthesized NiCo-LDH-CQDs-20 exhibits the high specific capacitance of 1814 F g(-1) at 1 A g(-1). When the current density is increased to 15 A g(-1), the specific capacitance value remains 75.5 % of the initial one, which indicates that NiCo-LDH-CQDs-20 has an extremely high-rate performance. Furthermore, the asymmetric supercapacitor NiCo-LDH-CQDs-20//AC provides a high energy density of 46.47 Wh kg(-1) in 2 M KOH solution with a power density of 800 W kg(-1) and maintains an initial specific capacitance of 82.7 % after 2000 cycles. Therefore, this study provides a promising approach for the development of anode active materials in supercapacitor energy storage devices.

Low-cost non-noble metal catalyst for dehydrogenation of formic acid to hydrogen at near room temperature is considered as a key to promoting commercial technology for clean energy. We have constructed reduced graphene oxide (RGO) self-assembly bonded nickel particles for synthesis of graphene nanosheets embedded with nickel nanoparticles architecture Ni@xRGO. Nitrogen and oxygen co-doped graphene facilitates the adsorption of hydrogen protons from formic acid. Electron transfer ability of Ni@xRGO with active sites is enhanced via Ni-C bond in the interface between the RGO nanosheets and nickel particles, which promoted the C-H bond breaking for dehydrogenation of formic acid. The Ni@0. 20RGO has excellent catalytic performance for hydrogen production from formic acid at near room temperature (the yield of hydrogen, 240.0 mL g-1 h-1 at 50 degrees C), comparable to the most active non-noble metal catalysts. (c) 2021 Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC.

The speed of the oxygen evolution reaction seriously affects the hydrogen production ef-ficiency of water electrolysis. Hence it is crucial to develop efficient and durable OER electrocatalysts. Construction of heterojunction catalysts is also one of the strategies to develop efficient catalysts. In this paper, a pea-like Cu/Cu2S-C3 Mott-Schottky electro-catalyst was self-constructed by vapor deposition, while CF (copper foam) was used as substrate material and copper source, and thiourea was served as sulfur source. The built-in electric field is formed at the metal-semiconductor interface, which endows it with promising electrocatalytic performance. As the working electrode, the overpotentials of Cu/Cu2S-C3 required to reach the current density of 10 and 50 mA cm-2 were about 170 and 335 mV. The impact of the Mott-Schottky structure on the catalyst was also reflected in stability. The i-t tests of the sample Cu/Cu2S-C3 were carried out under 10 and 60 mA cm-2 and performed well.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Direct pyrolysis/KOH activation of carbon from castor shell biomass is an economical combination of two processes to breakdown biomass lignin effectively. The advanced liquid nitrogen-controlled direct pyrolysis/KOH activation technique is even a shortened process, which optimizes the fugacious bond reformation for enhancing supercapacitors’ performance. Novel quenching of the red-hot activated carbon (heated at 800 °C) in liquid nitrogen is peculiar to the demonstrated structural changes. The desired throughput designated nKAC exhibited a high specific surface area of 1468 m 2 g −1 over the initial 1131 m 2 g −1 for KAC. In 6 M KOH electrolyte, the nKAC electrode exhibited a high specific capacitance of 481 F g −1 at 1 A g −1 and an excellent rate capability of 298 F g −1 at 30 A g −1 . In symmetric two electrodes test, the electrodes of nKAC show a high energy density of 17.75 Wh kg −1 at 0.5 A g −1 in 1 M Na 2 SO 4 electrolyte compared with 14.75 Wh kg −1 of KAC electrodes. Furthermore, the nKAC still maintained a high energy density of 12.4 Wh kg −1 at 5.0 A g −1 corresponding to a high power density of 4500 W kg −1 . This simple and green method has potential applications in the synthesis of porous carbon based on waste biomass for enhancing performance of electrode materials.

An effective and low-cost nanocatalyst is designed for formic acid (FA) dehydrogenation to boost practical applications. Herein, we report superior PdCoNi nanoparticles (NPs) supported on Schiff base conjugated carbon nitride, which exhibits excellent catalytic performance with a turnover frequency (TOF) of 1308 h(-1) on FA decomposition to hydrogen at room temperature. The results show that the Schiff base groups grafted on the carbon nitride support contribute to providing abundant conjugated active sites for anchoring metal, leading to the formation of ultrafine and well-dispersed PdCoNi NPs (1.70 nm) with electron-rich Pd species, which are responsible for the outstanding catalytic activity. The conjugated Schiff base can also facilitate the O-H bond dissociation on FA, which further promotes the decomposition of FA. This low-cost and high-performance palladium-based catalyst is conducive to the development of composite catalysts on FA dehydrogenation.

以氮修饰的炭黑为载体制备负载型PdCu/N-CB系列催化剂,相比较于未经氮修饰的催化剂,其催化性能显著提高,其中Pd8Cu2/N-CB催化剂活性最高,TOF为718.56 h-1,并呈现良好稳定性.通过XRD、TEM、FTIR和XPS等表征分析,结果表明,经APTMS处理所制得的氮修饰载体N-CB促进了所负载的PdCu合金纳米颗粒变得细小并呈现良好的分散性,活性相PdCu合金与氮修饰的载体N-CB之间存在强相互作用,调变合金颗粒表面化学态,提高了催化剂催化甲酸分解制氢性能.通过引入过渡金属和氮修饰载体来改善负载型贵金属催化剂催化性能的方法有助于低成本高性能制氢催化剂开发.

The fine Co3O4 particles derived from ZIF-67 induced self-assembly of NiNH to form sandwich layered Co3O4/NiNH with oxygen vacancies which showed high specific capacity. A Co3O4/NiNH//AC supercapacitor has high energy density and cycle stability.