The ever-increasing energy density of the Li-ion battery calls for utilization of high-capacity cathodes and anodes, which tend to be more reactive and thus bring serious safety concern. Under such context, the solid-state Li battery becomes a hotspot because of its potential in the breakthrough of energy density as well as the avoidance of uncontrollable chemical reactions. Recently, many review and perspective papers appear, addressing the urgency of improving solid-electrolytes' ionic conductivity and constructing stable conductive interfaces between electrolyte and electrode with respect to available electrolytes, including polymers, nitrides, sulfides, and oxides. Nevertheless, each type of electrolyte has its own distinctive problems, which is worthwhile specifically elaborating in order to find effective solutions. Therefore, here, we present our viewpoints on the key issues related to the garnet electrolytes and relevant batteries, which have not ever been dedicatedly addressed previously. On the basis of our recent progress, together with others reported in the literature, we expect that the solid garnet batteries are promising for application if the best use is made of garnet advantages and disadvantages are bypassed.

Conductive nanomaterials have recently gained a lot of interest due to their excellent physical, chemical, and electrical properties, as well as their numerous nanoscale morphologies, which enable them to be fabricated into a wide range of modern chemical and biological sensors. This study focuses mainly on current applications based on conductive nanostructured materials. They are the key elements in preparing wearable electrochemical Biosensors, including electrochemical immunosensors and DNA biosensors. Conductive nanomaterials such as carbon (Carbon Nanotubes, Graphene), metals and conductive polymers, which provide a large effective surface area, fast electron transfer rate and high electrical conductivity, are summarized in detail. Conductive polymer nanocomposites in combination with carbon and metal nanoparticles have also been addressed to increase sensor performance. In conclusion, a section on current challenges and opportunities in this growing field is forecasted at the end.

Solid-state batteries with alkali metals (Li, Na, etc.) as anodes have the potential to achieve high energy density. However, the Li penetration through the garnet occurs without preindication during electrochemical cycling, leading to sudden short circuit and safety concerns. Various improvement strategies are developed but such a problem still exists when the current density exceeds the critical value. In contrast, the electrochemical Na plating/stripping on the β″-alumina ceramic electrolyte (BASE) has been explored with improved interfacial contacts by introducing an Au intermediate layer. When being cycled around the critical current density, the polarization potential of the Na/ Au/BASE symmetric cells increases progressively until it stabilizes at a certain value without the sudden short circuit. It is revealed that the increasing polarization originates from a gradual Na penetration into the BASE ceramics from the interface and the subsequent stable cycles correlate with the formation of a sustainable Na/Au/BASE interface. These results disclose the difference in a growth model of metal filaments through Li and Na solid electrolytes, shedding new light on understanding of the metal penetration in solid electrolytes.

The oxidation of atrazine herbicide from water was performed by using titanium dioxide (TiO2) nanoparticles synthesized via the sol-gel method. A batch-scale photocatalytic reactor was designed for experimental work. The process was monitored using a UV–visible spectrophotometer. Operational parameters such as catalyst loading and pollutant concentration were investigated. The X-ray diffraction confirmed the anatase phase and high purity of the synthesized particles. Fourier transform infrared showed the functional group of titanium (Ti–O–Ti). The morphology of synthesized nanoparticles was characterized by scanning electron microscopy and transmission electron microscopy, which exhibited the irregular shape of nanoparticles along with aggregations. The average size of TiO2 was found to be 56.92 nm as measured from dynamic light scattering analysis. UV–visible spectrometry showed an absorbance of 0.13 (<1). The nanoparticles displayed UV light-responsive catalytic ability with a bandgap energy of 3.14 eV. Furthermore, atrazine was discovered using mass spectrometry, which revealed a clear and sharp peak at 173, 95, and 76 m/z, respectively, at collision energies of 16 and 24 eV. The photocatalytic activity of the TiO2 nanoparticles was examined for the degradation of atrazine. Overall, the obtained results displayed the great efficiency of TiO2 nanoparticles towards ultra-violet light, which was 92.56% at 100 mg of dosages, highlighting the great potential of the photocatalysis process for atrazine degradation. Furthermore, the process followed pseudo-first-order kinetics and the rate was seen to depend on catalyst loading.