This study demonstrates the fabrication of mesoporous tungsten trioxide (WO₃)-decorated flexible polyimide (PI) electrodes for the highly sensitive detection of catechol (CC) and hydroquinone (HQ), two environmental pollutants. Organic–inorganic composite dots are formed on flexible PI electrodes using evaporation-induced self-assembly (EISA) and electrospray methods. The EISA process is induced by a temperature gradient during electrospray, and the heated substrate partially decomposes the organic parts etched by O₂ plasma, creating mesoporous structures. Differential pulse voltammetry and cyclic voltammetry demonstrate a linear correlation between analyte concentration and the electrochemical response. Computational studies support the spontaneous adsorption of CC and HQ molecules on model WO₃ surfaces. The proposed sensor shows high sensitivity, a wide linear range, and a low detection limit for both individual and simultaneous determination of CC and HQ. Real sample analysis on river water confirms practical applicability. The WO₃-decorated PI electrode presents an efficient and reliable approach for detecting these pollutants, contributing to environmental safety measures.

The exploration of heterostructures composed of two-dimensional (2D) transition metal dichalcogenide (TMDc) materials has garnered significant research attention due to the distinctive properties of each individual component and their phase-dependent unique properties. Using the plasma-enhanced chemical vapor deposition (PECVD) method, we analyze the fabrication of heterostructures consisting of two phases of molybdenum disulfide (MoS₂) in four different cases. The initial hydrogen evolution reaction (HER) polarization curve indicates that the activity of the heterostructure MoS₂ is consistent with that of the underlying MoS₂, rather than the surface activity of the upper MoS₂. This behavior can be attributed to the presence of Schottky barriers, which include contact resistance, which significantly hampers the efficient charge transfer at junctions between the two different phases of MoS₂ layers and is mediated by van der Waals bonds. Remarkably, the energy barrier at the junction dissipates upon reaching a certain electrochemical potential, indicating surface activation from the top phase of MoS₂ in the heterostructure. Notably, the 1T/2H MoS₂ heterostructure demonstrates enhanced electrochemical stability compared to its metastable 1T-MoS₂. This fundamental understanding paves the way for the creation of phase-controllable heterostructures through an experimentally viable PECVD, offering significant promise for a wide range of applications.

The material loss caused by bubble collapse during the micro-nano bubbles auxiliary chemical mechanical polishing (CMP) process cannot be ignored. In this study, the material removal mechanism of cavitation in the polishing process was investigated in detail. Based on the mixed lubrication or thin film lubrication, bubble–wafer plastic deformation, spherical indentation theory, Johnson–Cook (J–C) constitutive model, and the assumption of periodic distribution of pad asperities, a new model suitable for micro-nano bubble auxiliary material removal in CMP was developed. The model integrates many parameters, including the reactant concentration, wafer hardness, polishing pad roughness, strain hardening, strain rate, micro-jet radius, and bubble radius. The model reflects the influence of active bubbles on material removal. A new and simple chemical reaction method was used to form a controllable number of micro-nano bubbles during the polishing process to assist in polishing silicon oxide wafers. The experimental results show that micro-nano bubbles can greatly increase the material removal rate (MRR) by about 400% and result in a lower surface roughness of 0.17 nm. The experimental results are consistent with the established model. In the process of verifying the model, a better understanding of the material removal mechanism involved in micro-nano bubbles in CMP was obtained.