The thermodynamically favorable electrocatalytic oxidation coupled with hydrogen evolution reaction (HER) is considered as a sustainable and promising technique. Nonetheless, it remains a great challenge due to the lack of simple, cheap, and high-efficient electrocatalysts. Here, we successfully develop a simple and scalable electro-deposition and subsequent phosphorization route to fabricate Ni-doped Co₂P (Ni-Co₂P) nanosheets catalyst using the in-situ released Ni species from defective Ni foam as metal source. Impressively, the as-synthesized Ni-Co₂P catalyst exhibits excellent electrochemical 5-hydroxymethylfurfural oxidation reaction (HOR) performance with > 99% 2,5-furandicarboxylic acid yield and > 97% Faradaic efficiency at an ultralow potential of 1.29 V vs. reversible hydrogen electrode (RHE). Experimental characterization and theoretical calculation reveal that the atomically doped Ni species can enhance the adsorption of reactant and thus lower the reaction energy barriers. By coupling the electrocatalytic HOR with HER, the employed two-electrode system using Ni-Co₂P and commercial Ni foam as anode and cathode, respectively, exhibits a low cell voltage of 1.53 V to drive a current density of 10 mA·cm⁻², which is 90 mV lower than that of pure water splitting. This work provides a facile and efficient approach for the preparation of high-performance earth-abundant electrocatalysts toward the concurrent production of H₂ and value-added chemicals.

Sodium-ion batteries (SIBs) are considered the most up-and-coming complements for large-scale energy storage devices due to the abundance and cheap sodium. However, due to the bigger radius, it is still a great challenge to develop anode materials with suitable space for the intercalation of sodium ions. Herein, we present hard carbon microtubes (HCTs) with tunable apertures derived from low-cost natural kapok fibers via a carbonization process for SIBs. The resulted HCTs feature with smaller surface area and shorter Na⁺ diffusion path benefitting from their unique micro-nano structure. Most importantly, the wall thickness of HCTs could be regulated and controlled by the carbonization temperature. At a high temperature of 1,600 °C, the carbonized HCTs possess the smallest wall thickness, which reduces the diffusion barrier of Na⁺ and enhances the reversibility Na⁺ storage. As a result, the 1600HCTs deliver a high initial Coulombic efficiency of 90%, good cycling stability (89.4% of capacity retention over 100 cycles at 100 mA·g⁻¹), and excellent rate capacity. This work not only charts a new path for preparing hard carbon materials with adequate ion channels and novel tubular micro-nano structures but also unravels the mechanism of hard carbon materials for sodium storage.

Organic synthesis driven by heterogeneous catalysis is a central research theme to both fundamental research and industrial production of fine chemicals. However, the employment of stoichiometric strong oxidizing or reducing reagents (e.g., K₂Cr₂O₇ and LiAlH₄) and harsh reaction conditions (e.g., high temperature and pressure) always leads to the products of overreaction and other by-product residues (e.g., salt and acid waste). Thus the poor control of product selectivity and tremendous energy consumption result in the urgent demand to develop novel technologies for heterogeneous catalysis. Given the current global theme of development in CO₂ reduction and sustainable energy utilization, one promising protocol is heterogeneous photocatalysis. It enables sustainable solar-to-chemical energy conversion under mild conditions (e.g., room temperature, ambient pressure, and air as the oxidant) and offers unique reaction pathways for improved selectivity control. To accurately tailor the selectivity of desired products, the electronic structure (e.g., positions of valence-band maximum and conduction-band minimum), geometric structure (e.g., nanorod, nanosheet, and porous morphology), and surface chemical micro-environment (e.g., vacancy sites and co-catalysts) of heterogeneous photocatalysts require rational design and construction. In this review, we will briefly analyze some effective photocatalytic systems with the excellent regulation ability of product selectivity in organic transformations (mainly oxidation and reduction types) under visible light irradiation, and put forward opinions on the optimal fabrication of nanostructured photocatalysts to realize selective organic synthesis.

Synergistically combining biological whole-cell bacteria with man-made semiconductor materials innovates the way for sustainable solar-driven CO₂ fixation, showing great promise to break through the bottleneck in traditional chemical photocatalyst systems. However, most of the biohybrids require uneconomical organic nutrients and anaerobic conditions for the successful cultivation of the bacteria to sustain the CO₂ fixation, which severely limits their economic viability and applicability for practical application. Herein, we present an inorganic-biological hybrid system composed of obligate autotrophic bacteria Thiobacillus thioparus (T. thioparus) and CdS nanoparticles (NPs) biologically precipitated on the bacterial surface, which can achieve efficient CO₂ fixation based entirely on cost-effective inorganic salts and without the restriction of anaerobic conditions. The optimized interface between CdS NPs and T. thioparus formed by biological precipitation plays an essential role for T. thioparus efficiently receiving photogenerated electrons from CdS NPs and thus changing the autotrophic way from chemoautotroph to photoautotroph. As a result, the CdS–T. thioparus biohybrid realizes the solar-driven CO₂ fixation to produce multi-carbon glutamate synthase and biomass under visible-light irradiation with CO₂ as the only carbon source. This work provides significant inspiration for the further exploration of the solar-driven self-replicating biocatalytic system to achieve CO₂ fixation and conversion.

Replacement of enzymes with nanomaterials such as atomically dispersed metal catalysts is one of the most crucial steps in addressing the challenges in biocatalysis. Despite the breakthroughs of single-atom catalysts in enzyme-mimicking, a fundamental investigation on the development of an instructional strategy is still required for mimicking biatomic/multiatomic active sites in natural enzymes and constructing synergistically enhanced metal atom active sites. Herein, Fe₂NC catalysts with atomically dispersed Fe-Fe dual-sites supported by the metal-organic frameworks-derived nitrogen-doped carbon are employed as biomimetic catalysts to perform proof-of-concept investigation. The effect of Fe atom number toward typical oxidase (cytochrome C oxidase, NADH oxidase, and ascorbic acid oxidase) and peroxidase (NADH peroxidase and ascorbic acid peroxidase) activities is systematically evaluated by experimental and theoretical investigations. A peroxo-like O₂ adsorption in Fe₂NC nanozymes could accelerate the O–O activation and thus achieve the enhanced enzyme-like activities. This work achieves the vivid simulation of the enzyme active sites and provides the theoretical basis for the design of high-performance nanozymes. As a concept application, a colorimetric biosensor for the detection of S^2– in tap water is established based on the inhibition of enzyme-like activity of Fe₂NC nanozymes.

Cu-based electrocatalysts have provoked much attention for their high activity and selectivity in carbon dioxide (CO₂) conversion into multi-carbon hydrocarbons. However, during the electrochemical reaction, Cu catalysts inevitably undergo surface reconstruction whose impact on CO₂ conversion performance remains contentious. Here we report that polycrystalline Cu nanoparticles (denoted as Cu-s) with rich high-index facets, derived from Cu_2−xS through desulphurization and surface reconstruction, offer an excellent platform for investigating the role of surface reconstruction in electrocatalytic CO₂ conversion. During the formation of Cu-s catalyst, the two stages of desulphurization and surface reconstruction can be clearly resolved by in situ X-ray absorption spectroscopy and OH⁻ adsorption characterizations, which are well correlated with the changes in electrocatalytic performance. It turns out that the high CO₂ conversion performance, achieved by the Cu-s catalyst (Faradic efficiency of 68.6% and partial current density of 40.8 mA/cm² in H-cell toward C₂H₄ production), is attributed to the increased percentage of high-index facets in Cu-s during the surface reconstruction. Furthermore, the operando electrochemical Raman spectroscopy further reveals that the conversion of the CO₂ into the C₂H₄ on Cu-s is intermediated by the production of *COCHO. Our findings manifest that the surface reconstruction is an effective method for tuning the reaction intermediate of the CO₂ conversion toward high-value multicarbon (C₂₊) chemicals, and highlight the significance of in situ characterizations in enhancing the understanding of the surface structure and its role in electrocatalysis.

Developing carbon-based electrocatalysts with excellent N₂ adsorption and activation capability holds the key to achieve highly efficient nitrogen reduction reaction (NRR) for reaching its practical application. Here, we report a highly active electrocatalyst— metal-free pyrrolic-N dominated N, S co-doped carbon (pyrr-NSC) for NRR. Based on theoretical and experimental results, it is confirmed that the N and S-dopants practice a working-in-tandem mechanism on pyrr-NSC, where the N-dopants are utilized to create electropositive C sites for enhancing N₂ adsorption and the S-dopants are employed to induce electron backdonation for facilitating N₂ activation. The synergistic effect of the pyrrolic-N and S-dopants can also suppress the irritating hydrogen evolution reaction, further boosting the NRR performance. This work gives an indication that the combination of two different dopants on electrocatalyst can enhance NRR performance by working in the two tandem steps—the adsorption and activation of N₂ molecules, providing a new strategy for NRR electrocatalyst design.

Crystal phase engineering on photocatalytic materials is a subfield of photocatalysis with intensive research, which has been proven as a versatile approach to maneuver their performance for applications in energy- and environment-related fields. In this article, the state-of-the-art progress on phase-engineered photocatalytic materials is reviewed. Firstly, we discuss the phase engineering on pristine semiconductor photocatalysts, in which the phase-dependent light absorption, charge transfer and separation, and surface reaction behaviors in photocatalytic processes are summarized, respectively. Based on the elucidated mechanisms, the implementation of phase junctions in photocatalytic reactions is then presented. As a focus, we highlight the rational design of phase junctions toward steering the charge kinetics for enhanced photocatalytic and photoelectrocatalytic performance. Moreover, the crystal phase engineering on semiconductor-based hybrid photocatalysts is also introduced, which underlines the importance of choosing a suitable phase for semiconductor components and co-catalysts as well as the synergism of different semiconductor phases for improved photocatalytic performance. Finally, the challenges and perspectives in this research field are proposed. In this review, particular emphasis is placed on establishing a linkage between crystal phase and photocatalytic activity to develop a structure-activity guide. Based on the guide, a framework is suggested for future research on the rational phase design of photocatalysts for improved performance in energy and environmental applications.

To fully realize the commercial viability of Pt in fuel cells, the usage of scarce Pt must be reduced while the activity and durability in O₂ reduction reaction (ORR) must be enhanced. Here we report a metallic stack design achieving these goals for ORR, based on atomically precise materials synthesis. Au@Pd@Pt nanostructures with atomically thin Pt shells and high-index surfaces form an excellent platform for integrating the effects of electronic structures, surface facets, and substrate stabilization to boost ORR performance. Au@Pd@Pt trisoctahedrons (TOH) achieve mass activity 6.1 times higher than that of commercial Pt/C and dramatically enhanced durability beyond 1.0 V vs. a reversible hydrogen electrode in oxidation potential. Meanwhile, Pt comprises only 3.2% of the nanostructures. To further improve the ORR activity and demonstrate the versatility of our strategy, we implement the same design in PtNi alloy electrocatalysts. The Au@Pd@PtNi TOHs exhibit mass activity 14.3 times higher than that of commercial Pt/C as well as excellent durability. This work demonstrates an alternative strategy for fabricating high-performance and low-cost catalysts, and highlights the importance of simultaneous surface and interfacial engineering with atomic precision in designing catalysts.

Stealth coating materials effectively extend a nanoparticle's systemic circulation lifetime yet limit its cellular internalization, which promotes and prevents tumor targeting, respectively. Here, this contradiction was resolved by using an acutely pH-sensitive zwitterionic stealth ligand capable of responding to small differences in extracellular pH between blood and tumors. Using a photothermal gold nanocage (AuNC) as a model nanotherapeutic, we found that stealth-AuNC nanoparticles showed both significantly enhanced cell uptake efficiency in acidic tumors and a markedly extended systemic circulation lifetime compared to its unaltered analogue. As a result, stealth-AuNC nanoparticles administered intravenously showed significantly enhanced accumulation within the tumor, leading to significantly improved photothermal therapeutic efficacy in mouse models. These results suggests that pH-sensitive zwitterionic ligands with sufficient sensitivity for responding to small differences in extracellular pH between blood and tumors are ideal stealth materials for simultaneously conferring both extended systemic circulation and enhanced cellular internalization, reducing the need for active targeting moieties.