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The development of conductive coatings has significant implications for microelectronics and electrochemistry. However, conductive coatings may exhibit different electrochemical properties when prepared on different substrate materials. This research explores the comparative performance of graphene, graphene oxide (GO), and silver nanoparticle (Ag NP) composites as conductive coatings on diverse substrate materials, including polydimethylsiloxane (PDMS), polymethyl methacrylate (PMMA), and glass. The study employed various preparation methods, such as mixing conductive materials with substrate materials and preparing copolymer composite materials. The conductive coating approach was found to be the most straightforward and convenient, with broader development prospects and fewer restrictive conditions. The results indicate that the distinct surface characteristics of the substrate materials influence the conductive properties of coating materials. Consequently, results show that graphene exhibits the highest conductivity on all three substrates, while GO is more conductive than Ag NPs on PMMA and PDMS but less conductive than Ag NPs on glass. That offers valuable insights into the selection of substrate materials and coating materials for the preparation of conductive materials.

Under the background of peak carbon dioxide emissions and achieving carbon neutrality, clean energy technologies such as water electrolysis, metal–air batteries, and fuel cells have attracted extensive attention due to the advantages of high efficiency, good safety, a simple structure, low cost, and eco-friendliness. However, the key reactions on oxygen catalytic electrodes, the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), are kinetically sluggish, which considerably hinders their commercial applications. The traditional oxygen catalytic electrodes with the use of binders have the disadvantages of a cumbersome synthesis process, low controllability, poor uniformity, high cost, and easy carrier catalyst agglomeration, which limit their catalytic performance. Recently, self-supported oxygen catalytic electrodes have attracted extensive attention due to their advantages of high catalytic active sites and a stabilized spatial framework, which can solve the problems faced by traditional oxygen catalytic electrodes and further improve the catalytic performance of the electrode. As the catalyst material carrier, the substrate materials play an important role in the catalytic performance of self-supporting oxygen electrodes. The high interaction forces between the substrate and the catalyst material lead to a single-direction growth orientation and uniform dispersion. Reportedly, the substrate materials for self-supporting oxygen catalytic electrodes have not been fully discussed in comprehensive reviews. Therefore, timely updates in this potential field must be provided. This paper summarizes the research progress and synthesis methods of commonly self-supporting oxygen catalytic electrodes based on different substrate materials, including two- and three-dimensional metal materials and carbon materials. In addition, this paper introduces the outstanding ORR/OER catalytic properties of common self-supporting oxygen catalytic electrodes, which are not only due to the intrinsic catalytic activity of the supported catalytic active materials but also related to the high specific surface area and high electron transfer rate caused by the structure of the self-supported electrode substrate. Finally, the future research and the development trend of self-supporting oxygen catalytic electrodes are addressed from the four aspects of density general function theory, improving electrode energy density, constructing an efficient gas–liquid–solid three-phase interface of an electrode, and establishing a standard evaluation protocol of self-supported oxygen catalytic electrodes. This review should provide new research insights for developing renewable energy storage and conversion systems.

Rapid, sensitive, and accurate detection of adrenoceptor agonists is a significant research topic in the fields of food safety and public health. Immunoassays are among the most widely used methods for detecting adrenoceptor agonists. In recent years, surface-enhanced Raman spectroscopy combined with immunoassay (SERS-IA) has become an effective technique for improving detection sensitivity. This review focuses on the innovation of Raman reporter molecules and substrate materials for the SERS-IA of adrenoceptor agonists. In addition, it also investigates the challenges involved in potentially applying SERS-IA in the detection of adrenoceptor agonists. Overall, this review provides insight into the design and application of SERS-IA for the detection of adrenoceptor agonists, which is critical for animal-derived food safety and public health.

In this paper, a rectangular microstrip patch antenna (MPA) is designed using different substrate materials for analyzing the performance of the MPA. Alumina (Al2O3), Bakelite, Beryllium oxide (BeO), Gallium Arsenide (GaAs), RT-Duroid and Flame Retardant 4 (FR-4) are the six different substrate used in the design. The size of the rectangular microstrip patch antenna varies according to the dielectric constant of substrate materials used. The operating frequency taken for this analysis is 5.8 GHz. The proposed design provides the study on the performance of rectangular microstrip patch antenna for different substrate materials using the same frequency. This study conveys that which substrate material provides better performance. Moreover, this comparative study conveys that which substrate material provides better performance. The simulation parameters are investigated using HFSS.

The selection of appropriate substrate material acts as a performance regulator for miniaturized graphene patch antenna. The substrate material not only controls the transport properties of graphene but also influences the resonant properties of the graphene patch antenna. The edge fed microstrip line graphene based rectangular patch antenna is designed here for operating in the frequency range 2.67–2.92 THz for wireless applications. The performance is investigated for silicon nitride, aluminum oxide, boron nitride, silica and quartz substrate materials on the basis of return loss, voltage standing wave ratio (VSWR), absorption cross section, bandwidth and radiation efficiency. The comparison of results shows that silicon nitride exhibits overall excellent performance by the virtue of having higher bandwidth and radiation efficiency as compared to other chosen substrate materials.

Existing regulations on the thermal efficiency of building envelope assemblies are based on the steady state thermal properties of substrate materials. Heat transfer mechanisms of passive heat curbing methods such as phase change materials and cool materials, which are dynamic in nature, are currently not being accounted for. The effectiveness of thermo-physical and solar radiation properties of building materials (i.e., solid homogeneous layers without air gap) in reducing the heat gain into a building in a hot climate could be well understood with the equivalent thermal resistance (Req) concept. A simple and easy-to-use mathematical derivation (i.e., to estimate the instantaneous heat flux across an envelope assembly) is proposed in this paper to understand the mechanism of equivalent R-value (i.e., reciprocal of thermal transmittance, U-value) due to solar radiation properties of passive substrate materials. The model is validated against field experiments carried out at two apartment units of a residential building. The Req due to high outer surface solar radiation properties (i.e., by applying a cool coating) is dynamic as it varies with the weather conditions. The effect of a substrate material’s solar radiation and thermo-physical properties on the overall roof thermal performance is investigated using the Req model for four cooling dominated climates around the globe, having different diurnal conditions and sky temperatures. Increasing the outer surface’s solar reflectance (from 10% to 80%) reduces net heat gain through the flat roof during both daytime and nighttime. In contrast, adding only thermal resistance (from 5 mm to 75 mm thick polyurethane) or volumetric heat capacity (by adding 5 mm thick phase change material) to the building envelope brings down heat gain during the day, but not in the night. Thermal insulation is found to be the second effective property, followed by thermal mass irrespective of different diurnal conditions and sky temperatures across the climates.