The development of novel and effective methods for the activation of methane is fascinating, which offers a promising potential for the sustainable development of chemical industry and the mitigation of greenhouse effect. Here we successfully synthesize two-dimensional (2D) Zr/5,10,15,20-tetrakis (4-carboxyphenyl) porphyrin (TCPP) ultrathin nanobelts (UNBs) as a high efficiency catalyst for methane (CH₄) oxidation to carbon monoxide (CO). The Co-UNBs show well photo-coupled electrocatalytic performances for CH₄ activation (CO production rates are 0.171 and 8.416 mmol·g⁻¹·h⁻¹ under dark/visible light, respectively). Density functional theory (DFT) calculations were performed to illustrate the mechanism of photoelectrocatalytic process and the high efficiency oxidation of CH₄ to CO. Based on the ultrathin structure and highly efficient catalytic properties, this work provides a prospecting avenue for the design and synthesis of methane oxidation catalyst.

It is important and challenging to analyze nanocluster structure with atomic precision. Herein, α-hemolysin nanopore was used to identify nanoclusters at the single molecule level by providing two-dimensional (2D) dwell time–current blockage spectra and translocation event frequency which sensitively depended on their structures. Nanoclusters such as Anderson, Keggin, Dawson, and a few lacunary Dawson polyoxometalates with very similar structures, even with only a two-atom difference, could be discriminated. This nanopore device could simultaneously measure multiple nanoclusters in a mixture qualitatively and quantitatively. Furthermore, molecular dynamics (MD) simulations provided microscopic understandings of the nanocluster translocation dynamics and yielded 2D dwell time–current blockage spectra in close agreement with experiments. The nanopore platform provides a novel powerful tool for nanocluster characterization.

Achieving stable surface structures of metal catalysts is an extreme challenge for obtaining long-term durability and meeting industrial application requirements. We report a new class of metal catalyst, Pt-rich PtCu heteroatom subnanoclusters epitaxially grown on an octahedral PtCu alloy/Pt skin matrix (PtCu_1.60), for the oxygen reduction reaction (ORR) in an acid electrolyte. The PtCu_1.60/C exhibits an 8.9-fold enhanced mass activity (1.42 A·mg_Pt⁻¹) over that of commercial Pt/C (0.16 A·mg_Pt⁻¹). The PtCu_1.60/C exhibits 140,000 cycles durability without activity decline and surface PtCu cluster stability owing to unique structure derived from the matrix and epitaxial growth pattern, which effectively prevents the agglomeration of clusters and loss of near-surface active sites. Structure characterization and theoretical calculations confirm that Pt-rich PtCu clusters favor ORR activity and thermodynamic stability. In room-temperature polymer electrolyte membrane fuel cells, the PtCu_1.60/C shows enhanced performance and delivers a power density of 154.1/318.8 mW·cm⁻² and 100 h/50 h durability without current density decay in an air/O₂ feedstock.

Structure–activity relationship (SAR) is the key problem of nanoscience, thus to fabricate novel and well-defined nanostructure will provide a new insight on catalyst preparation method. Highly active and low cost electrocatalysts for oxygen evolution reaction (OER) are of great importance for future renewable energy conversion and storage. Herein, NiFe-based layered double hydroxides with laminar structure (NFLS) were successfully fabricated via a one-step hydrothermal approach by using sodium dodecyl sulfate as surfactant. The as-fabricated NFLS showed a well-defined periodic layered-stacking geometry with a scale down to 1-nm. Benefitting from the unique structure, NFLS exhibited an excellent catalytic activity towards OER with current densities of 10 mA·cm⁻² at overpotential of 197 mV. The synergistic effect of Ni and Fe plays a key role in electrode reactions. The present work provides a new insight to improve the OER performance by rational design of electrocatalysts with unique structures.

Construction of macro-materials with highly oriented microstructures and well-connected interfaces between building blocks is significant for a variety of applications. However, it is still challenging to confine the desired structures. Thus, well-defined building blocks would be crucial to address this issue. Herein, we present a facile process based on 1.8 nm Pd nanoclusters (NCs) to achieve centimeter-size assemblages with aligned honeycomb structures, where the diameter of a single tubular moiety is ~4 μm. Layered and disordered porous assemblages were also obtained by modulating the temperature in this system. The reconciled interactions between the NCs were crucial to the assemblages. As a comparison, 14 nm Pd nanoparticles formed only aggregates. This work highlights the approach of confining the size of the building blocks in order to better control the assembly process and improve the stability of the structures.

We perform detailed quantum chemical calculations to elucidate the origin and mechanism of the selective permeability of alkali and alkaline earth cation-decorated graphene oxide (M-GO) membranes to organic solvents. The results show that the selectivity is associated mainly with the transport properties of solvents in the membranes, which depends on two regions of the flow path: the sp³ C–O matrix of the GO sheets and the cation at the center of the hexagon rather than the sp² region. According to the delocalization of π states in sp² regions, we propose a design guide for high-quality M-GO membranes. The solvent–cation interaction essentially causes directional transport of molecules in the M-GO membranes under the transmembrane pressure, indicating a site-to-site mechanism. The solvent–sp³ C–O matrix interaction may inhibit molecular transport between two fixed cations by consuming energy. The competition between energy consumption by the solvent–cation interaction and energy expenditure by the solvent–sp³ C–O matrix interaction leads to various transport properties of solvents and thus allows for the selective permeability of the M-GO membranes. Findings from the study are helpful for the future design of multifunctional M-GO macro-membranes as cost-effective solution nanofilters in chemical, biological, and medical applications.

Developing low-cost and high-efficiency photocatalysts for hydrogen production from solar water splitting is intriguing but challenging. In this study, unique one-dimensional (1D) multi-node MoS₂/CdS hetero-nanowires (NWs) for efficient visible-light photocatalytic H₂ evolution are synthesized via a facile hydrothermal method. Flower-like sheaths are assembled from numerous defect-rich O-incorporated {0001} MoS₂ ultrathin nanosheets (NSs), and {1120}- facet surrounded CdS NW stems are grown preferentially along the c-axis. Interestingly, the defects in the MoS₂ NSs provide additional active S atoms on the exposed edge sites, and the incorporation of O reduces the energy barrier for H₂ evolution and increases the electric conductivity of the MoS₂ NSs. Moreover, the recombination of photoinduced charge carriers is significantly inhibited by the heterojunction formed between the MoS₂ NSs and CdS NWs. Therefore, in the absence of noble metals as co-catalysts, the 1D MoS₂ NS/CdS NW hybrids exhibit an excellent H₂-generation rate of 10.85 mmol·g^–1·h^–1 and a quantum yield of 22.0% at λ = 475 nm, which is far better than those of Pt/CdS NWs, pure MoS₂ NSs, and CdS NWs as well as their physical mixtures. Our results contribute to the rational construction of highly reactive nanostructures for various catalytic applications.

A simple and reproducible method to control the thickness of black phosphorus flakes in real time using a UV/ozone treatment is demonstrated. Back-gated black phosphorus field-effect transistors (FETs) were fabricated using thick black phosphorus flakes obtained by thinning of black phosphorus, as oxygen radicals generated by UV irradiation formed phosphorus oxides on the surface. In order to monitor the thickness effect on the electrical properties, the fabricated FETs were loaded in the UV/ozone chamber, where both the optical (micro-Raman spectroscopy and optical microscopy) and electrical properties (current–voltage characteristics) were monitored in situ. We observed an intensity decrease of the Raman modes of black phosphorus while the field-effect mobility and on/off ratio increased by 48% and 6,800%, respectively. The instability in ambient air limits the investigation and implementation of ultra-thin black phosphorus. However, the method reported in this study allowed us to start with thick black phosphorous flakes, providing a reliable approach for optimizing the electrical performance of black phosphorus-based electronic devices. We believe that these results can motivate further studies using mono- and few-layer black phosphorus.