MoS₂/RGO composite hollow microspheres were hydrothermally synthesized by using SiO₂/GO microspheres as a template, which were obtained via the sonication-assisted interfacial self-assembly of tiny GO sheets on positively charged SiO₂ microspheres. The structure, morphology, phase, and chemical composition of MoS₂/RGO hollow microspheres were systematically investigated by a series of techniques such as FE-SEM, TEM, XRD, TGA, BET, and Raman characterizations, meanwhile, their electrochemical properties were carefully evaluated by CV, GCD, and EIS measurements. It was found that MoS₂/RGO hollow microspheres possessed unique porous hollow architecture with high-level hierarchy and large specific surface area up to 63.7 m²·g⁻¹. When used as supercapacitor electrode material, MoS₂/RGO hollow microspheres delivered a maximum specific capacitance of 218.1 F·g⁻¹ at the current density of 1 A·g⁻¹, which was much higher than that of contrastive bare MoS₂ microspheres developed in the present work and most of other reported MoS₂-based materials. The enhancement of supercapacitive behaviors of MoS₂/RGO hollow microspheres was likely due to the improved conductivity together with their distinct structure and morphology, which not only promoted the charge transport but also facilitated the electrolyte diffusion. Moreover, MoS₂/RGO hollow microsphere electrode displayed satisfactory long-term stability with 91.8% retention of the initial capacitance after 1000 charge/discharge cycles at the current density of 3 A·g⁻¹, showing excellent application potential.

Transition metal oxides (TMOs) have attracted extensive research attentions as promising electrocatalytic materials. Despite low cost and high stability, the electrocatalytic activity of TMOs still cannot satisfy the requirements of applications. Inspired by kinetics, the design of hollow porous structure is considered as a promising strategy to achieve superior electrocatalytic performance. In this work, cubic NiO hollow porous architecture (NiO HPA) was constructed through coordinating etching and precipitating (CEP) principle followed by post calcination. Being employed to detect glucose, NiO HPA electrode exhibits outstanding electrocatalytic activity in terms of high sensitivity (1323 μA mM−1 cm−2) and low detection limit (0.32 μM). The excellent electrocatalytic activity can be ascribed to large specific surface area (SSA), ordered diffusion channels, and accelerated electron transfer rate derived from the unique hollow porous features. The results demonstrate that the NiO HPA could have practical applications in the design of nonenzymatic glucose sensors. The construction of hollow porous architecture provides an effective nanoengineering strategy for high-performance electrocatalysts.

Flexible piezoresistive pressure sensors have attracted a great deal of attention because of their potential applications in areas such as human motion detection and health monitoring. The attachment of conducting polymers to the surface of microstructured Polydimethylsiloxane (PDMS) thin films is one effective method of preparing flexible pressure sensors. However, enhancing the interfacial adhesion of the conductive polymer and PDMS to prevent flaking and improve performance stability is a key issue. Here, we replicated the surface of a discarded vinyl record to create a PDMS film with wrinkled microstructures, reducing manufacturing costs and enabling the use of waste. A flexible, transparent and microdefect-free polyaniline film (PANI) with a thickness of 320 nm was prepared. The protonated PANI film (PPF) was tightly adhered to the microstructured surface of the PDMS film to prepare a PPF@PDMS flexible pressure sensor. The pressure-sensitive performance of the sensor remained stable after fatigue testing of 7000 loads, which proves the strong adhesion of the two films. Based on its high sensitivity (0.24 kPa⁻¹), low detection limit (2 Pa), and fast response capability (15 ms), the sensor can detect weak physiological behaviours (breathing, pulse) as well as large body movements (finger bending, finger pressing, etc.). Cyclic vibration waves from the engine can also be recognized. The excellent performance demonstrates the potential application of the PPFP sensor in the field of human health monitoring.

Cadmium sulphide (CdS) quantum dots (QDs), sensitizing hierarchical bismuth oxychloride (BiOCl) photocatalysts, were synthesized via a facile solvothermal approach and characterized in detail. The as-prepared CdS–BiOCl photocatalyst possessed an extended light absorption range and efficient charge separation properties simultaneously compared with pure BiOCl, especially in the visible light region. The results revealed that the newly formed oxygen vacancies will play an important role in the visible light degradation process, which resulted in the efficient separation of photogenerated electron–hole pairs, and a large increase in photocatalytic activity.

Nickel silicate hydroxide/reduced graphene oxide (Ni3Si2O5(OH)4/RGO) composite hollow microspheres were one-pot hydrothermally synthesized by employing graphene oxide (GO)-wrapped SiO2 microspheres as the template and silicon source, which were prepared through sonication-assisted interfacial self-assembly of tiny GO sheets on positively charged SiO2 substrate microspheres. The composition, morphology, structure, and phase of Ni3Si2O5(OH)4/RGO microspheres as well as their electrochemical properties were carefully studied. It was found that Ni3Si2O5(OH)4/RGO microspheres featured distinct hierarchical porous morphology with hollow architecture and a large specific surface area as high as 67.6 m2 g–1. When utilized as a supercapacitor electrode material, Ni3Si2O5(OH)4/RGO hollow microspheres released a maximum specific capacitance of 178.9 F g−1 at the current density of 1 A g−1, which was much higher than that of the contrastive bare Ni3Si2O5(OH)4 hollow microspheres and bare RGO material developed in this work, displaying enhanced supercapacitive behavior. Impressively, the Ni3Si2O5(OH)4/RGO microsphere electrode exhibited outstanding rate capability and long-term cycling stability and durability with 97.6% retention of the initial capacitance after continuous charging/discharging for up to 5000 cycles at the current density of 6 A g−1, which is superior or comparable to that of most of other reported nickel-based electrode materials, hence showing promising application potential in the energy storage area.

Inspired by kinetics, the design of hollow hierarchical electrocatalysts through large-scale integration of building blocks is recognized as an effective approach to the achievement of superior electrocatalytic performance. In this work, a hollow, hierarchical Co ₃ O ₄ architecture (Co ₃ O ₄ HHA) was constructed using a coordinated etching and precipitation (CEP) method followed by calcination. The resulting Co ₃ O ₄ HHA electrode exhibited excellent electrocatalytic activity in terms of high sensitivity (839.3 μ A mM ⁻¹ cm ⁻² ) and reliable stability in glucose detection. The high sensitivity could be attributed to the large specific surface area (SSA), ample unimpeded penetration diffusion paths and high electron transfer rate originating from the unique two-dimensional (2D) sheet-like character and hollow porous architecture. The hollow hierarchical structure also affords sufficient interspace for accommodation of volume change and structural strain, resulting in enhanced stability. The results indicate that Co ₃ O ₄ HHA could have potential for application in the design of non-enzymatic glucose sensors, and that the construction of hollow hierarchical architecture provides an efficient way to design highly active, stable electrocatalysts.