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High-entropy alloys (HEAs) present both significant potential and challenges for developing efficient electrocatalysts due to their diverse combinations and compositions. Here, we propose a procedural approach that combines high-throughput experimentation with data-driven strategies to accelerate the discovery of efficient HEA electrocatalysts for the hydrogen evolution reaction (HER). This enables the rapid preparation of HEA arrays with various element combinations and composition ratios within a model system. The intrinsic activity of the HEA arrays is swiftly screened using scanning electrochemical cell microscopy (SECCM), providing precise composition–activity data sets for the HEA system. An ensemble machine learning (EML) model is then used to predict the activity database for the composition subspace of the system. Based on these database results, two groups of promising catalysts are recommended and validated through actual electrocatalytic evaluations. This procedural approach, which combines high-throughput experimentation with data-driven strategies, provides a new pathway to accelerate the discovery of efficient HEA electrocatalysts.

Dyes and antibiotics as typical persistent organic pollutants (POPs) are widely present in the environment, but can hardly be removed completely by traditional water treatment methods. Here, we designed Bi4O5Br2/g-C3N4composite nanosheets for efficient photocatalytic removal of POPs in water. The Bi4O5Br2/g-C3N4composite with a heterojunction structure exhibited high adsorption and photocatalytic activity for removal of tetracycline (TC) and ciprofloxacin (CIP) with excellent cyclic stability, owing to its large specific surface area as well as enhanced charge separation and visible light utilization. Our characterization revealed that h+and ·OH are responsible for the photocatalytic degradation of TC and CIP. This work provides insights into the design of photocatalytic materials with synergy of adsorption and photocatalytic degradation, and offers a heterojunction construction strategy for addressing the increasingly severe environmental issues. The Bi4O5Br2/g-C3N4composite with a heterojunction structure was fabricated by a hydrothermal method. The Bi4O5Br2/g-C3N4composite exhibits high adsorption and photocatalytic activity for removal of tetracycline (TC) and ciprofloxacin (CIP) with excellent cyclic stability due to its large specific surface area as well as enhanced charge separation and visible light utilization.

Highly active oxygen evolution reaction (OER) electrocatalysts are important to effectively transform renewable electricity to fuel and chemicals. In this work, we construct a series of multimetal oxide nanoplate OER electrocatalysts through successive cation exchange followed by electrochemical oxidation, whose electronic structure and diversified metal active sites can be engineered viathe mutual synergy among multiple metal species. Among the examined multimetal oxide nanoplates, CoCeNiFeZnCuOxnanoplates exhibit the optimal adsorption energy of OER intermediates. Together with the high electrochemical active surface area, the CoCeNiFeZnCuOxnanoplates manage to deliver a small overpotential of 211 mV at an OER current density of 10 mA cm–2(η10) with a Tafel slope as low as 21 mV dec–1in 1 M KOH solution, superior to commercial IrO2(339 mV at η10, Tafel slope of 55 mV dec–1), which can be stably operated at 10 mA cm–2(at an overpotential of 211 mV) and 100 mA cm–2(at an overpotential of 307 mV) for 100 h.

A carbon microtube aerogel (CMA) with hydrophobicity, strong adsorption capacity, and superb recyclability was obtained by a feasible approach with economical raw material, such as kapok fiber. The CMA possesses a great adsorption capacity of 78–348 times its weight. Attributed to its outstanding thermal stability and excellent mechanical properties, the CMA can be used for many cycles of distillation, squeezing, and combustion without degradation, which suggests a potential practical application in oil–water separation. In addition, the adsorption capacity still retained 98% by distillation, 97% by squeezing, and 90% by combustion after 10 cycles. Therefore, the obtained CMA has a broad prospect as an economical, efficient, and environmentally friendly adsorbent.

Electrocatalysts are one of the most important parts for oxygen evolution reaction (OER) to overcome the sluggish kinetics. Herein, amorphous Fe–Ni–P–B–O (FNPBO) nanocages as efficient OER catalysts are synthesized by a simple low-cost and scalable method at room temperature. The samples are chemically stable, in clear contrast to reported unstable or even pyrophoric boride samples. The Fe/Ni ratio of the FNPBO nanocages can be continuously adjusted to optimize the OER catalytic performance. The FNPBO nanocages composed of multicomponent elements can weaken the metal–metal bonds, thus rearranging the electron density around the catalytic metal atom centers and reducing the energy barrier for intermediate formation. Hence the optimized FNPBO (Fe6.4Ni16.1P12.9B4.3O60.2) catalyst shows superior intrinsic electrocatalytic activity for OER. The low overpotential to afford the current density of 10 mA cm–2(236 mV), the small Tafel slope (39 mV dec–1), and the high specific current density (26.44 mA cm–2) at a given overpotential of 300 mV make a sharp contrast to state-of-the-art RuO2(327 mV, 136 mV dec–1, and 0.028 mA cm–2, respectively).

g-C3N4is a promising visible-light-driven photocatalyst for H2evolution reaction; however, the achievement of the high photocatalytic performance is primarily limited by the low separation efficiency of the photogenerated charge carriers and partly restricted by the slow kinetics of charge transfer. 2D g-C3N4can significantly improve the charge generation, transfer, and separation efficiencies. The 2D g-C3N4-based Z-scheme heterostructure can further enhance the charge-carrier separation and simultaneously increase the redox ability, thereby further boosting the photocatalytic performance. Here we report a transition-metal-oxide (TMO)-mediated subtractive manufacturing process toward the large-scale synthesis of 2D g-C3N4and the simultaneous formation of a 2D/2D TMO/g-C3N4Z-scheme heterojunction. The TMOs serve as catalysts to facilitate the hydrolysis reaction of the bulk g-C3N4in the presence of moist air, forming 2D g-C3N4. The resulting 2D/2D TMO/g-C3N4catalysts, in particular, 2D/2D Co3O4/g-C3N4, exhibit high-efficiency and high-yield photocatalytic H2evolution due to the suppression of electron–hole pair recombination and enhanced redox ability. The 2D/2D Co3O4/g-C3N4photocatalyzes the H2evolution with a rate of ∼370 μmol h–1within λ > 400 nm. The external quantum efficiency of 2D/2D Co3O4/g-C3N4at λ = 405 nm reaches 53.6%, which is among the highest values for g-C3N4-based catalysts.

Molybdenum disulfide (MoS2) has attracted much attention as a promising alternative to Pt-based catalysts for highly efficient hydrogen generation. However, it suffers sluggish kinetics for driving the hydrogen evolution reaction (HER) process because of inert basal planes, especially in alkaline solution. Here, we show a combination of heteroatom doping and phase transformation strategies to engineer the in-plane structure of MoS2, that trigger their catalytic activities. Systematic characterizations are performed with advanced aberration-corrected microscopy and X-ray techniques, indicating that an as-designed MoS2catalyst has a distorted zigzag-chain superlattice in metallic phase, while its in-plane structure was engineered viathe incorporation of cobalt and oxygen species. The optimal Co, O dual-doped metallic phase molybdenum disulfide (1T-MoS2) electrocatalyst shows a significantly enhanced HER activity with a low overpotential of 113 mV at 10 mA cm–2and corresponding small Tafel slope of 50 mV dec–1, accompanied by the robust stability in alkaline media. The calculated turnover frequency is higher than 6.65 H2s–1at an overpotential of 200 mV. More in-depth insights from the first-principle calculations illustrate that the water dissociation as a rate-determining step was largely accelerated by the in-plane Co–O–Mo species and fast electron transfer of the catalyst. Benefiting from ingenious design and fine identifications, this work provides a fundamental understanding of the relationships among heteroatom doping, phase transformation, and performance for MoS2-based catalysts.

Developing metal-free catalysts with high catalytic activity for oxygen evolution reaction (OER) is essentially important for energy and environment-related techniques. Compared with individual element doping, doping carbon materials with multiple heteroelements has more advantages for enhancing the OER performance. However, doped sites for the different atoms are highly uncontrollable under the reported methods, which hinder the deeper understanding on the relationship between structure and property, and also limit the enhancement of catalytic activity. Our latest research has reported a method to site-controlled introducing a new form of nitrogen atoms, i.e. sp-hybridized nitrogen (sp-N), into graphdiyne, showing its potential advantages in OER catalysis. Since the sites of sp-N atoms are defined in graphdiyne, and the doping sites for S atoms are well understood, the relative position between N and S can be further defined. It gives us a chance to understand deeply the mechanism in the N, S heteroelements doped metal-free catalyst. Experimental results present that the codoping of sp-N and S atoms brought an excellent OER performance with low overpotential and high current density owning to the effectively synergistic effect of the stereodefined heteroatoms.

The oxygen reduction reaction (ORR) is a fundamental reaction for energy storage and conversion. It has mainly relied on platinum-based electrocatalysts, but the chemical doping of carbon-based materials has proven to be a promising strategy for preparing metal-free alternatives. Nitrogen doping in particular provides a diverse range of nitrogen forms. Here, we introduce a new form of nitrogen doping moieties —sp-hybridized nitrogen (sp-N) atoms into chemically defined sites of ultrathin graphdiyne, through pericyclic replacement of the acetylene groups. The as-prepared sp-N-doped graphdiyne catalyst exhibits overall good ORR performance, in particular with regards to peak potential, half-wave potential and current density. Under alkaline conditions it was comparable to commercial Pt/C, and showed more rapid kinetics. And although its performances are a bit lower than those of Pt/C in acidic media they surpass those of other metal-free materials. Taken together, experimental data and density functional theory calculations suggest that the high catalytic activity originates from the sp-N dopant, which facilitates O2adsorption and electron transfer on the surface of the catalyst. This incorporation of chemically defined sp-N atoms provides a new synthetic route to high-performance carbon-based and other metal-free catalysts. Heteroatom doping is a widely used modification method for carbon-based catalysts. Now, chemically defined sp-hybridized nitrogen atoms have been selectively introduced to the acetylene groups in ultrathin graphdiynes, resulting in good catalytic activity for the oxygen reduction reaction in both alkaline and acidic media.

Two-dimensional stable metallic 1T-MoSe2with expanded interlayer spacing of 10.0 Å in situgrown on SWCNTs film is fabricated viaa one-step solvothermal method. Combined with X-ray absorption near-edge structures, our characterization reveals that such 1T-MoSe2and single-walled carbon nanotubes (abbreviated as 1T-MoSe2/SWCNTs) hybridized structure can provide strong electrical and chemical coupling between 1T-MoSe2nanosheets and SWCNT film in a form of C–O–Mo bonding, which significantly benefits a high-efficiency electron/ion transport pathway and structural stability, thus directly enabling high-performance lithium storage properties. In particular, as a flexible and binder-free Li-ion anode, the 1T-MoSe2/SWCNTs electrode exhibits excellent rate capacity, which delivers a capacity of 630 mAh/g at 3000 mA/g. Meanwhile, the strong C–O–Mo bonding of 1T-MoSe2/SWCNTs accommodates volume alteration during the repeated charge/discharge process, which gives rise to 89% capacity retention and a capacity of 971 mAh/g at 300 mA/g after 100 cycles. This synthetic route of a multifunctional MoSe2/SWCNTs hybrid might be extended to fabricate other 2D layer-based flexible and light electrodes for various applications such as electronics, optics, and catalysts.

Understanding the intrinsic relationship between the catalytic activity of bimetallic nanoparticles and their composition and structure is very critical to further modulate their properties and specific applications in catalysts, clean energy, and other related fields. Here we prepared new bimetallic Pt–Ru nanoparticles with different Pt/Ru molar ratios via a solvothermal method. In combination with X-ray diffraction (XRD), transmission electron microscopy (TEM) coupled with energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), and synchrotron X-ray absorption spectroscopy (XAS) techniques, we systematically investigated the dependence of the methanol electro-oxidation activity from the obtained Pt/Ru nanoparticles with different compositions under annealing treatment. Our observations revealed that the Pt–Ru bimetallic nanoparticles have a Pt-rich core and a Ru-rich shell structure. After annealment at 500 °C, the alloying extent of the Pt–Ru nanoparticles increased, and more Pt atoms appeared on the surface. Notably, subsequent evaluations of the catalytic activity for the methanol oxidation reaction proved that the electrocatalytic performance of Pt/Ru bimetals was increased with the oxidation degree of superficial Ru atoms.

The emerging single atom catalysts (SACs) with tailorable, uniform and well-defined metal sites provide an ideal platform for studying the atomic-level correlation between structural configuration and catalytic behavior on heterogeneous catalysis. Here we demonstrate the electronic synergy of neighboring Ir and Ni diatomic sites on carbon supports (IrNi-N-C) for promoting the hydrogen evolution. The catalyst exhibits superior catalytic activity with low overpotentials (28 and 45 mV at 10 mA cm−2) and high turnover frequencies (TOFs, 3.06 and 1.40 H2s−1at 50 mV) in acidic and alkaline electrolytes, respectively. Theoretical and experimental results suggest that the incorporation of adjacent Ni-N4moiety increases the occupancy of Ir 5d orbitals and shifts the d-band center down in the IrNi-N-C catalyst, thus facilitating the catalytic process by the optimal intermediate binding energy. This work highlights the significance of Ni 3d-Ir 5d electronic coupling between neighboring single metal sites for catalytic activity, and paves a way for the SACs design by manipulating d-d electronic interaction except for tuning of the coordination ligands and the electronic metal-support interactions.

Aqueous aluminum metal batteries (AMBs) are regarded as one of the most sustainable energy storage systems among post-lithium-ion candidates, which is attributable to their highest theoretical volumetric capacity, inherent safe operation, and low cost. Yet, the development of aqueous AMBs is plagued by the incapable aluminum plating in an aqueous solution and severe parasitic reactions, which results in the limited discharge voltage, thus making the development of aqueous AMBs unsuccessful so far. Here, we demonstrate that amorphization is an effective strategy to tackle these critical issues of a metallic Al anode by shifting the reduction potential for Al deposition. The amorphous aluminum (a-Al) interfacial layer is triggered by an in situ lithium-ion alloying/dealloying process on a metallic Al substrate with low strength. Unveiled by experimental and theoretical investigations, the amorphous structure greatly lowers the Al nucleation energy barrier, which forces the Al deposition competitive to the electron-stealing hydrogen evolution reaction (HER). Simultaneously, the inhibited HER mitigates the passivation, promoting interfacial ion transfer kinetics and enabling steady aluminum plating/stripping for 800 h in the symmetric cell. The resultant multiple full cells using Al@a-Al anodes deliver approximately a 0.6 V increase in the discharge voltage plateau compared to that of bare Al-based cells, which far outperform all reported aqueous AMBs. In both symmetric cells and full cells, the excellent electrochemical performances are achieved in a noncorrosive, low-cost, and fluorine-free Al2(SO4)3electrolyte, which is ecofriendly and can be easily adapted for sustainable large-scale applications. This work brings an intriguing picture of the design of metallic anodes for reversible and high-voltage AMBs.

Enhancing activity and stability of iridium- (Ir-) based oxygen evolution reaction (OER) catalysts is of great significance in practice. Here, we report a vacancy-rich nickel hydroxide stabilized Ir single-atom catalyst (Ir1–Ni(OH)2), which achieves long-term OER stability over 260 h and much higher mass activity than commercial IrO2in alkaline media. In situ X-ray absorption spectroscopy analysis certifies the obvious structure reconstruction of catalyst in OER. As a result, an active structure in which high-valence and peripheral oxygen ligands-rich Ir sites are confined onto the nickel oxyhydroxide surface is formed. In addition, the precise introduction of atomized Ir not only surmounts the large-range dissolution and agglomeration of Ir but also suppresses the dissolution of substrate in OER. Theoretical calculations further account for the activation of Ir single atoms and the promotion of oxygen generation by high-valence Ir, and they reveal that the deprotonation process of adsorbed OH is rate-determining.

Developing highly active and stable photocatalysts is a crucial endeavor to harvest valuable carbon-based fuels and feedstocks for photocatalytic CO2conversion. The excellent photocatalysts must satisfy the thermodynamic condition for the redox reaction and possess the accelerated reaction kinetics. Here, we report a strategy using grain-boundary surface terminations and oxygen vacancies to synergistically and selectively boost photocatalytic CO2reduction activity. Thereinto, grain boundaries as bulk defects create high-energy surfaces by stabilizing dislocations that are kinetically trapped for catalysis owing to the lattice strain of the photocatalyst. Oxygen vacancies are used to tailor the band structure and enhance the adsorption ability of reactants or intermediates. High-energy surface structures arisen from these bulk defects may be more resistant to the relaxation effect, resulting in excellent stability for photocatalytic CO2reduction. In light of the anticipated increase for photocatalytic CO2reduction activity, this work provides a strategy for broader exploitation of bulk defects in heterogeneous catalysis.