Preparation of Cu-loaded porous metal oxide catalysts for the catalytic upgrading of wood tar in supercritical methanol

Advances in MOF-derived porous carbons, oxides, and hybrids for water splitting and beyond

A macroscopic P-ZIF-8/PDA/MF adsorbent was fabricated by substituting conventional zinc precursors with layered porous zinc oxide (P-ZnO) on polydopamine (PDA)-functionalized melamine foam (MF). The composite exhibited exceptional adsorption capacity for chlortetracycline hydrochloride from wastewater, with a Langmuir-modeled maximum of 1320 mg/g at pH 6. Systematic evaluation of environmental parameters─including pH gradients, ionic strength variations, and competitive ion interference─revealed robust performance under various aqueous conditions. In addition, FT-IR and XPS analyses were performed to characterize P-ZIF-8/PDA/MF both prior to adsorption and following the adsorption process in order to clarify its adsorption behavior. The analysis indicates that the uptake by P-ZIF-8/PDA/MF mainly proceeds through monolayer chemisorption, which results from the combined contributions of hydrogen-bond interactions, π-π stacking, and pH-dependent electrostatic attraction.

Enhanced Durability of Pt/C Electrocatalysts with Protective Porous Niobium Oxide Nanocoatings

Hydrogen production via photoelectrochemical (PEC) water splitting is a promising approach for efficient renewable-energy storage and transport. This study investigates a proton exchange membrane (PEM)-PEC system using pure water operated without adding supporting electrolyte. A porous tungsten oxide (WO3) photoanode was surface-modified with a perfluorosulfonic acid (PFSA) ionomer coating. Under 365-nm UV irradiation and an applied cell voltage of 1.2 V, the PFSA ionomer-modified WO3 electrode improved the incident photon-to-current conversion efficiency (IPCE) from 15% to 36% compared with the unmodified electrode. The pure water-fed system achieved an IPCE of 35%, comparable to vapor-fed systems, despite requiring less than one-tenth of the ionomer loading (0.06 mg cm-2), indicating a stronger ionomer effect in aqueous environments. Product analysis confirmed oxygen evolution at the WO3 electrode and hydrogen at the cathode, with nearly all photocurrent contributing to water splitting. The photocurrent density proportionally increased with light intensity and followed the bandgap absorption of WO3. These results demonstrate that PFSA ionomer loading effectively eliminates proton transport limitations in electrolyte-free conditions, highlighting the importance of surface protonics of the porous photoanodes in PEM-PEC systems.

HighlightsPreparation of ordered nanohole array with a heterointerface of metal oxides by anodizationFormation of metal thin films with dimple patterns that act as the starting point for pore growth in the initial stage of anodizationOptimization of anodization conditions to obtain an ordered anodic porous oxide

Advanced detection systems increasingly rely on infrared (IR) imaging to overcome the limitations of visible light cameras in adverse environments such as fog, rain, and low-light conditions. However, the effectiveness of IR detection remains fundamentally constrained by the low emissivity contrast between targets and their backgrounds. Here, we present a plasmonic metal-dielectric-metal nanostructure comprising a porous anodic aluminum oxide (AAO) dielectric layer sandwiched between an aluminum substrate and a surface Au nanoparticle layer that enables near-independent modulation of visible reflectance (400-800 nm) and long-wave infrared emissivity (8-14 μm). The decoupling mechanism exploits the distinct characteristic length scales governing each spectral band: visible reflectance is controlled by Fabry-Pérot cavity interference and plasmonic absorption of the Au nanoparticle layer, while infrared emissivity is governed by the intrinsic phonon absorption of the AAO layer and is insensitive to Au coverage. Using scalable anodic oxidation and screen-printing fabrication, we achieve tunable visible reflectance (R = 0.2-0.9) and infrared emissivity (ε = 0.1-0.87). Applied to infrared-enhanced license plate detection, our patterned plates achieve an average recognition rate of ∼45% under adverse environmental conditions, compared to ∼5% for conventional plates. This work offers a scalable route to multispectral patterned surfaces for infrared imaging, thermal sensing, and anticounterfeiting applications.

The combustion efficiency and energy release capacity of solid rocket propellants (SRPs) are predominantly determined by the thermal decomposition behavior of ammonium perchlorate (AP), the core oxidizer. Developing high-efficiency catalysts and deciphering their intrinsic catalytic mechanisms remain a critical challenge. In this work, Ti4+ substitution modulates the distance between Co-Co active sites, triggering a unique intersite distance effect (ISDE) in hierarchical porous Co2TiO4 nanoflower catalysts. Their catalytic performance and intrinsic mechanism for AP thermal decomposition were systematically investigated. The shorter Co-Co active site distance enhances the electronic synergistic effect by enabling a stable "bridged adsorption" dual-site mechanism, potentially breaking the scaling relations between intermediate adsorption energies, and thus significantly improving catalytic performance. This ISDE synergizes with the hierarchical porous structure, optimizing the electronic structure of Co sites (the d-band center shifts 0.3 eV toward the Fermi level), enhancing the adsorption and activation capacity of reaction intermediates, and regulating the NH3 oxidation pathway, increasing the selectivity of NO2 to 48.4%, accompanied by an accelerated decomposition rate and more concentrated exothermic behavior. Density functional theory (DFT) calculations further verify that Ti substitution adjusts the surface electrostatic potential and adsorption energy of reactants, facilitating the cleavage of N-H and Cl-O bonds in NH3 and HClO4, respectively. This work clarifies the critical role of ISDE in mediating catalytic activity and provides a new theoretical paradigm for the rational design of high-performance bimetallic oxide catalysts for energetic material applications, particularly in SRPs.

Abstract Photoelectrochemical (PEC) water splitting is a promising strategy for providing clean, sustainable fuel. However, its efficiency is limited by the high overpotential and sluggish kinetics of the oxygen evolution reaction. To improve oxidation kinetics and produce a higher-value product, it is possible to oxidize organic molecules instead. One such molecule is 5-hydroxymethylfurfural (HMF), which can be converted into the high-value platform chemical 2,5-furandicarboxylic acid (FDCA). In this study, we used porous tungsten oxide (WO₃) photoanodes to oxidize HMF photoelectrochemically. Our work focuses on electrolyte selection for this conversion reaction, and we therefore conducted a detailed reproducible study. Furthermore, we carried out a mechanistic investigation and studied the capability of oxidizing the reaction intermediates to support our electrolyte choice. Using the most suitable electrolytes in a self-designed flow-cell setup enabled us to produce FDCA (0.02 mM) for the first time using WO₃ photoanodes under AM 1.5 G illumination. Due to the identification of the side products maleic and formic acid, this work also provides knowledge for further optimization of PEC HMF oxidation.

Templating strategies for the synthesis of stimuli-responsive porous cerium oxide nanoparticles for pH-Triggered cargo encapsulation

Porous rare earth-based high-entropy perovskite oxide nanosheet for stable acidic water splitting at ampere-level current density

We present a comprehensive first-principles investigation of novel two-dimensional porous monolayers based on BeO, CdO, MgO, and ZnO, designed as ultra-wide-bandgap semiconductors (UWBG). Three distinct lattice topologies are explored: IGPD (inorganic graphenyldiene), featuring hexagonal arrangements of phenyl and Dewar-benzene-like units; INP (inorganic naphthylene), a tetragonal lattice composed of cyclobutadiene and naphthalene-like motifs; and INPD (inorganic naphthyldiene), a hybrid tetragonal framework combining structural features of IGPD and INP. All monolayers exhibit dynamic and thermal stability, confirmed by phonon dispersion calculations and ab initio molecular dynamics at 300 K. Mechanical analyses reveal that BeO-based lattices possess the highest stiffness and largest band gaps. Conversely, CdO-based structures are softer and more ductile. Bader charge analysis indicates a mixed ionic–covalent bonding character across all systems. The mechanical anisotropy varies according to lattice topology, with INP structures showing enhanced stiffness due to their compact motifs. These findings provide valuable insights into the design of stable, tunable 2D UWBG semiconductors with potential applications in future electronic and optoelectronic devices. • Novel 2D porous Be, Cd, Mg, and Zn oxide lattices with ultra-wide band gaps. • First-principles study reveals stability and mechanical properties of monolayers. • BeO-based lattices exhibit the highest stiffness and the largest band gaps. • Phonon analysis confirms dynamic stability with no imaginary frequencies. • Charge transfer analysis shows a mixed ionic–covalent bonding nature.

Two-dimensional (2D) nanomaterials offer exceptional properties for constructing advanced macroscopic materials. However, when assembled into 3D architectures, nanosheet stacking often restricts mass transport and reduces accessible active sites. Introducing in-plane pores in 3D macroscopic materials constructed with 2D nanomaterials has still faced great challenge. Herein, we present a monolithic holey 2D TiO2 aerogel composed of graphene-like nanosheets, successfully synthesized via a one-step "chemical vapor infiltration-deposition" coupling with "template-removal-driven crystallization under spatial confinement" strategy. This aerogel integrates a crystalline anatase framework with a unique 2D holey building morphology (exposing the {111} facet), a high specific surface area, and abundant surface defects (oxygen vacancies and Ti3+). It thus demonstrates excellent performance in photocatalytic degradation and UV shielding, outperforming conventional sol-gel-derived TiO2 aerogels composed of nanoparticle aggregates. Moreover, this aerogel shows promise as a candidate for wave-transparent materials. Our strategy concurrently achieves pore creation, crystallization, and 3D structuring, moving beyond the conventional "sheet-first, pore-later" sequence and opening one door for synthesizing advanced porous oxide nanosheets and their macro-architectures.

Layered double hydroxides (LDHs) are versatile 2D materials with highly tunable compositions and structures. However, existing strategies typically rely on composition-specific or phase-limited transformations, making the controlled construction of single-layer porous layered nanomaterials with diverse chemical matrices highly challenging. Therefore, the development of a general strategy for single-layer porous LDH-derived materials remains elusive. Here, we report a general and versatile synthetic framework in Mg-Al-based LDH systems that enables the controlled construction of single-layer porous layered nanomaterials with distinct chemical matrices derived from a common LDH precursor and tunable doping. Using Nd as a representative doping model, the systematic transformation from LDH to layered double oxides (LDO), layered double fluorides (LDF), and layered double oxysulfides (LDOS) was achieved while preserving an ultrathin porous 2D morphology. The generality of this approach was further demonstrated by extending the strategy to other dopant elements, spanning rare-earth and transition-metal systems. This unified platform allowed systematic correlation of matrix chemistry with functionality, including enhanced luminescence in rare-earth-doped fluorides, high magnetic relaxivity in porous oxides, and tunable band structures in transition-metal-doped oxysulfides. This work, therefore, established a general and versatile paradigm for designing multifunctional LDH-derived porous 2D materials.

The development of Sn-Zn lead-free solders is hindered by poor wettability caused by porous ZnO oxide films and high solid-liquid interfacial tension. This study introduces a Pt-Al coalloying strategy to achieve concurrent oxide film structure optimization and solid-liquid interfacial tension reduction. The results demonstrate that Al-alloying prompts chemical potential gradient-driven Al surface segregation, forming a dense amorphous Al-rich oxide layer at ZnO/matrix interfaces that inhibits oxygen permeation and reduces the oxide film thickness. Furthermore, Pt-Al coalloying enhances chemical potential gradients of Al between the bulk and surface (by generating preoxidized Al atoms with enhanced electropositivity while strengthening Al3+-O2- bonding in the oxide film), which accelerates Al surface segregation and promotes oxide layer densification, ultimately promoting oxide film thickness reduction. Meanwhile, under conditions of Pt-Al coalloying, element Pt segregation at solid-liquid interfaces enhances the ionic characteristic of interfacial bonding, reducing solid-liquid interfacial tension through strengthened atomic interactions. As a result, the Pt-Al cooperative effect markedly improves Sn-Zn solder wettability, reducing the equilibrium contact angle on Cu substrates from 38.2° for the Sn-9Zn solder to an optimal 25.1° for the Sn-9Zn-0.02Al-0.1Pt solder. However, Pt-Al coalloying also compromises Sn/Zn interfacial stability, enabling oxygen ingress along grain boundaries and promoting ZnO block nucleation. Beyond critical Pt concentrations (0.25 wt %), Al segregation at ZnO/matrix interfaces becomes insufficient to inhibit ZnO block growth, resulting in the degraded wettability. Consequently, Pt-Al coalloying requires precise optimization to balance oxide film structure optimization and interfacial stability.

Methanol aqueous reforming reaction (APRM) provides a green and clean route towards hydrogen production, in which the structure design and preparation of efficient catalysts remains a challenge. Herein, we report a platinum catalyst supported on the porous hydroxyl lanthanum oxide, which is prepared via glycine combustion method followed by a reduction process. The optimized 0.8%Pt/La catalyst, which is featured by Pt single-atom dispersed on a La2(OH)2 xO3-2 x support, exhibits an extraordinary catalytic performance towards APRM. A H2 production rate of 7672 µmolH2 gcat -1 min-1 and an average turnover frequency (ATOF) of 11973 h‒1 are obtained, which is preponderant to the state-of-the-art catalysts. An in-depth investigation based on kinetic isotope analysis, in situ spectroscopy characterizations and theoretical calculations substantiates that Pt single atom coordinated with adjacent lattice hydroxyl (OHL) with electron transfer from Pt to support serves as the intrinsic active site, in which the Ptδ + site promotes the dehydrogenation of methoxyl whilst lattice hydroxyl directly participates in the oxidative coupling process (CH2O* + OHL → CH2OOH*). Furthermore, the Ptδ +-(OHL)x-La interface sites can remarkably reduce the energy barrier of CH2OOH* dehydrogenation (rate-determining step), and the resulting hydroxyl vacancies can boost H2O dissociation to recover consumed OHL, accounting for the exceptional catalytic performance.

Graphene oxide (GO) membranes hold substantial promise for this application but are limited by structural instability in aqueous environments. This study introduces a composite membrane based on porous graphene oxide (PGO) with two-dimensional copper 1,4-benzenedicarboxylate (CuBDC) nanosheets grown in situ. The confined growth of CuBDC within the PGO laminar structure, via strong coordination between Cu2+ ions and oxygen-containing groups on PGO, not only stabilizes the PGO laminar structure but also induces NaCl rejection due to the appropriate pore size of the CuBDC. The resulting composite membrane demonstrated a high-water flux of 124 kg m−2 hour−1 in conventional pervaporation and 89 kg m−2 hour−1 in low-energy water carrier pervaporation, with NaCl rejection consistently above 99.9%. Technoeconomic analysis reveals that desalination using the fabricated membrane in a water-carrier pervaporation process results in a low annual expenditure. Overall, this study offers a promising strategy for stabilizing PGO membranes with excellent selectivity, paving the way for more energy-efficient desalination technologies.

Abstract Sulfur dioxide (SO₂), formaldehyde (HCHO), and carbon dioxide (CO₂) are common atmospheric pollutants that pose serious environmental and health risks. Although amine-based materials exhibit strong chemical affinity toward these gases, their practical performance is often limited by low surface area and weak sensing capability.In this work, a multifunctional oxide-polymer hybrid film was developed by integrating porous SiO₂ derived from rice-husk ash into a polyvinyl alcohol (PVA) matrix and subsequently functionalizing the structure with m-phenylenediamine (MPDA). The porous oxide framework enhances gas accessibility, while the amine groups provide active adsorption sites.Gas-amine interaction mechanisms were investigated using Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), while adsorption capacity and sensing behavior were evaluated through quartz crystal microbalance (QCM), thermogravimetric analysis (TGA), and electrical resistance measurements. Distinct chemisorption pathways were identified, including sulfite formation with SO₂, imine formation with HCHO, and carbamate formation with CO₂. Pure MPDA adsorbed 76.5 mg g -1 of SO₂ and 89.3 mg g -1 of HCHO, whereas incorporation into the porous PVA/SiO₂ composite significantly enhanced adsorption capacities to 373.7 mg g⁻¹ and 256.4 mg g -1 , respectively, representing improvements of up to 490%.In addition to enhanced adsorption, the composite film exhibited a pronounced resistive sensing response, with electrical resistance decreasing from 5 MΩ to 0.1 MΩ upon SO₂ exposure. Both adsorption capacity and sensing performance remained stable during repeated cycling. These results demonstrate that the amine-functionalized porous PVA/SiO₂ hybrid film provides an effective platform for simultaneous gas capture and sensing, highlighting its potential as a sustainable material for advanced environmental monitoring technologies.

Solution blow spun porous cobalt oxide nanofibers via cryogenic bath as oxygen evolution catalysts

General Construction of Porous Transition-Metal Oxide Nanosheets Derived from Single-Metal Precursors