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Perovskite solar cells (PSCs) with an inverted structure (often referred to as the p–i–n architecture) are attractive for future commercialization owing to their easily scalable fabrication, reliable operation and compatibility with a wide range of perovskite-based tandem device architectures 1 , 2 . However, the power conversion efficiency (PCE) of p–i–n PSCs falls behind that of n–i–p (or normal) structure counterparts 3 – 6 . This large performance gap could undermine efforts to adopt p–i–n architectures, despite their other advantages. Given the remarkable advances in perovskite bulk materials optimization over the past decade, interface engineering has become the most important strategy to push PSC performance to its limit 7 , 8 . Here we report a reactive surface engineering approach based on a simple post-growth treatment of 3-(aminomethyl)pyridine (3-APy) on top of a perovskite thin film. First, the 3-APy molecule selectively reacts with surface formamidinium ions, reducing perovskite surface roughness and surface potential fluctuations associated with surface steps and terraces. Second, the reaction product on the perovskite surface decreases the formation energy of charged iodine vacancies, leading to effective n-type doping with a reduced work function in the surface region. With this reactive surface engineering, the resulting p–i–n PSCs obtained a PCE of over 25 per cent, along with retaining 87 per cent of the initial PCE after over 2,400 hours of 1-sun operation at about 55 degrees Celsius in air. A reactive surface engineering approach is used to produce an inverted perovskite solar cell that reaches a power conversion efficiency of 25% and has good operational stability.

A detailed multi-step reaction mechanism is developed for modeling steam reforming of methane over nickel-based catalysts. The mechanism also includes partial and total oxidation reactions, water–gas shift reactions, formation of carbon monolayers, and methanation reactions. A method is presented for ensuring thermodynamic consistency in the development of surface reaction mechanisms. The applicability of the mechanism is tested by simulating experimental investigations of SR of methane on a Ni-coated monolithic cordierite catalyst as well as experimental studies from literature. The reactive flow in the channels of the experimentally used monolithic structures is modeled by a two-dimensional flow field analysis of a single monolith channel coupled with the reaction mechanism developed. The gas composition and surface coverage with adsorbed species are calculated as function of the position in the channel. The model developed is able to properly describe steam reforming of methane over the nickel catalysts for wide ranges of temperature and steam/methane ratio.

Different types of model catalysts and their characterization by a wide range of surface analysis techniques have been a successful approach to determine the activity and/or selectivity of catalytic processes, with the effects of surface structure and particle size being key aspects. In recent years, new types of model systems, exhibiting regions of different crystallographic orientations or different particle sizes within one sample have been established: polycrystalline foils of precious metals, consisting of many µm-sized domains of different structures, differently sized (from nm to mm) “curved” crystals with differently oriented facets and metal powder aggregates supported on thin oxide films. The signature property of such model systems is the possibility to examine the inherent catalytic properties of different crystallographic orientations/particle sizes simultaneously under identical reaction conditions by spatially-resolved kinetic experiments. Such heterogeneous model systems can be considered as “surface structure libraries” from which the desired surface structure can be chosen from dozens or even hundreds present on the specimen surface. Here, we review some new insights into catalytic ignition, reaction front propagation, oscillating surface reactions and long-ranging metal/oxide interface effects, gained by this approach. Graphical Abstract

This research aims to investigate the potential of novel CaF 2  − CaO − Na 2 O − B 2 O 3 −SiO 2 glass systems and converted to bioactive glass-ceramics. The study involves examining the effects of different heat treatment temperatures and immersion periods, with the goal of exploring these materials as viable alternatives for various biomedical applications. A typical melt-quenching technique was used to synthesize the glass samples, followed by a controlled heat treatment. The main crystalline phases are cuspidine and wollastonite, which have the potential to promote bioactivity, especially in dental and bone-related applications. The sample heat-treated at 700 °C showed an increased microhardness and fracture toughness by more than 116% and 36%, compared to the initial value. Furthermore, the increase in pH and the observed weight loss/gain demonstrated the reactivity of the samples with the phosphate buffer-saline medium, indicating their bioactive properties. Remarkably, the microhardness and fracture toughness exhibited notable improvements after 14 days of immersion, with an enhancement of 4.71% and 4.66%, highlighting their potential durability and longevity in high-strength dental crown applications. Consequently, this research presents a promising method for developing sustainable novel glass and glass-ceramic materials devoid of phosphates. These materials boast enhanced mechanical properties while preserving bioactivity, making them well-suited for dental implants and restorative purposes.

The catalytic surface interacts with the gas-phase by a variety of chemical and physical processes. Hence, optimization of design and operation conditions of catalytic reactors do not only require the understanding of the catalytic reaction sequence but also its coupling with mass and heat transport and potential homogeneous reactions. The chemical, thermal, and mass-transport interactions between the catalytic surface and the gas-phase are discussed in terms of the individual and combined interactions. The state-of-the-art modelling of reactive flows and its coupling with the catalytic surface is summarized. The interactions are illustrated by a number of examples such as reforming of hydrocarbons, catalytic combustion, exhaust-gas after-treatment, each focusing on a special aspect of catalyst–gas interactions. The potentials and limitations of the numerical simulations will be discussed including experimental techniques for model validation. Graphical Abstract

This work presents a study of the redox properties of CeO2 particles with (FeCeHS) and without (CeHS) Fe2O3 impregnation, as possible innovative catalysts for oxidation and combustion reactions as well as CO2 activation. The topic, therefore, is part of a broader analysis of environmental catalysis, which aims to reduce the emissions of polluting substances and improve the exploitation of energy resources, with consequent progress in the eco-friendly field. Different laboratory techniques (Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Ultraviolet–Visible (UV-Vis), and Fourier Transform–Infrared (FT-IR) spectroscopies) point out that iron oxide is deposited on the surface of ceria, which maintains its lattice structure, although the particle morphology is slightly changed. Methanol and ethanol adsorption and conversion were evaluated on these catalysts by Temperature Programmed Surface Reaction (TPSR) and by in situ FT-IR spectroscopy of the probe redox properties, evidencing the formation of surface oxidized intermediates and combustion products. The FeCeHS catalyst demonstrates, in our reaction conditions, a good combustion activity in total oxidation of oxygenated molecules, hindering the formation of formaldehyde from methanol and reducing the quantity of CO produced by the partial oxidation reaction. A cooperative effect is suggested by the mixture of these two metals in the oxidation process.

In this work, we revisited the single-step synthesis of CdE (E = S, Se, and Te) quantum dots (QDs). Powdered CdO and elemental chalcogen were directly used for heating-up synthesis. Firstly, the in situ dissolution of the solid precursors and related QD formation channels were preliminarily investigated. In general, QDs were generated from homogeneous reactions between dissolved cadmium and chalcogen precursors in bulk solution. We found that, during single-step synthesis, both the dissolution of CdO and selenium proceeded faster than their ex situ dissolution respectively. To explain this result, we proposed the existence of extra surface reaction channels for QD formation. That is, QDs could also be generated via on-surface reactions between the solid precursors and the dissolved counter precursors (as “ligands”). The happening of these extra surface reactions would increase the overall dissolution rate of CdO and selenium. Further, the circulation of oleic acid which is peculiar to such single-step synthesis should also partly account for the accelerated dissolution of CdO. Finally, by comparing with two-step synthesis using pre-dissolved CdO, we presented that such single-step synthesis was reliable in making uniform CdE QDs with good reproducibility. Our work reaffirmed the great potential of this single-step strategy in cost-effective synthesis of monodisperse QDs. Moreover, the ligand-promoted surface reaction channels would be applicable in solution-phase synthesis of metal chalcogenide nanocrystals from solid precursors.

In this study, quasi-two-dimensional BixSn1−xO2 (BTO) thin films were fabricated using a liquid metal transfer method. The ultraviolet (UV) photodetector based on BTO thin films was constructed, and the ultrahigh responsivity of 589 A/W was observed at 300 nm UV light illumination. Interestingly, by dropping ethanol during light-off period, the recovery time induced by the persistent photoconductivity (PPC) effect is reduced from 1.65 × 103 s to 5.71 s. Furthermore, the recovery time can also be reduced by dropping methanol, propylene glycol, NaNO2, and Na2SO3 after light termination. The working mechanisms are attributed to the rapid consumption of holes stored in BTO thin films by reaction with those solutions. This work demonstrates that the BTO thin films have potential applications in high-performance UV detectors and present an innovation route to weaken the PPC effects in semiconductors by introducing chemical liquids on their surface.

Ti-6Al-4V internal flow channels are difficult to finish because direct liquid metal-driven abrasive slurry polishing is constrained by both the limited driving capability of the liquid metal and the continuous formation of a dense surface reaction layer in alkaline electrolytes. In this study, the direct polishing behavior of Ti-6Al-4V flow channels was first investigated, and a distinct polishing capability boundary was identified through the evolution of surface morphology and areal roughness S[sub.a]. Although S[sub.a] decreased with polishing time, the reduction rate gradually diminished and eventually approached a plateau, indicating pronounced attenuation in effective material removal. Mechanistic analysis revealed that this limitation was governed by the dynamic formation and disruption of the oxide/reaction layer, which progressively shields the metallic substrate from direct abrasive action. To address this issue, an electric-field-assisted chemical pretreatment was introduced prior to the liquid metal-driven abrasive polishing stage, forming a two-step route (AB + P). Comparative experiments among direct polishing (P), chemical pretreatment followed by polishing (B + P), and electric-field-assisted chemical pretreatment followed by polishing (AB + P) showed that AB + P produced more homogeneous surface morphologies, lower S[sub.a], and a significantly weaker plateauing tendency than direct polishing. In addition, the attainable limiting surface quality was shifted to a lower level, indicating an extension of the polishing capability boundary. The influence of pretreatment electrification time further revealed the existence of an effective time window, beyond which the polishing improvement gradually saturated. These results demonstrate that electric-field-assisted chemical pretreatment is an effective strategy for mitigating polishing attenuation and enhancing the finishing capability of liquid metal-driven abrasive slurry polishing for Ti-6Al-4V internal flow channels.

In this paper we introduce a bulk-surface reaction-diffusion (BS-RD) model in three space dimensions (3D) that extends the so-called DIB morphochemical model to account for the electrolyte contribution in the application, in order to study structure formation during discharge-charge processes in batteries. Here we propose to approximate the model by the bulk-surface virtual element method (BS-VEM) on a tailor-made mesh that proves to be competitive with fast bespoke methods for PDEs on Cartesian grids. We present a selection of numerical simulations that accurately match the classical morphologies found in experiments. Finally, we compare the Turing patterns obtained by the coupled 3D BS-RD model with those obtained with the original 2D version.