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Bio-aerogels have emerged as promising materials for energy storage, providing a sustainable alternative to conventional aerogels. This review addresses their syntheses, properties, and characterization challenges for use in energy storage devices such as rechargeable batteries, supercapacitors, and fuel cells. Derived from renewable sources (such as cellulose, lignin, and chitosan), bio-based aerogels exhibit mesoporosity, high specific surface area, biocompatibility, and biodegradability, making them advantageous for environmental sustainability. Bio-based aerogels serve as electrodes and separators in energy storage systems, offering desirable properties such as high specific surface area, porosity, and good electrical conductivity, enhancing the energy density, power density, and cycle life of devices. Recent advancements highlight their potential as anode materials for lithium-ion batteries, replacing non-renewable carbon materials. Studies have shown excellent cycling stability and rate performance for bio-aerogels in supercapacitors and fuel cells. The yield properties of these materials, primarily porosity and transport phenomena, demand advanced characterization methods, and their synthesis and processing methods significantly influence their production, e.g., sol-gel and advanced drying. Bio-aerogels represent a sustainable solution for advancing energy storage technologies, despite challenges such as scalability, standardization, and cost-effectiveness. Future research aims to improve synthesis methods and explore novel applications. Bio-aerogels, in general, provide a healthier path to technological progress.

Nanocomposites comprising nitrogen-doped TiO 2 and reduced graphene oxide (N/TiO 2 /rGO), with different rGO loading qualities, were prepared by a cost-effective microwave-assisted synthesis method. The synthesized materials were broadly characterized by Raman spectroscopy, X-ray diffraction (XRD), infrared spectroscopy (FTIR), photoelectron spectroscopy (XPS), diffuse reflectance spectroscopy (DRS), electron microscopy (SEM-EDS), and nitrogen adsorption/desorption isotherms. Anatase was the only crystalline phase observed for all synthesized materials. The rGO loading did not affect the morphological properties, but it positively influenced the photocatalytic activity of the nanocomposite materials, especially at low rGO loading. Photocatalysts were evaluated via the degradation of specific organic micropollutant (OMP) pharmaceuticals: ciprofloxacin (CIP), diclofenac (DCF), and salicylic acid (SA), under different radiation sources: ultraviolet A (UVA), solar light simulator (SLS), blue visible light (BVL) and cold visible light (CVL). CIP and SA were removed effectively via the synergy of adsorption and photocatalysis, while DCF degradation was achieved solely by photocatalysis. After implementing scavenger agents, photocatalytic degradation processes mainly depended on the specific pollutant type, while irradiation sources barely defined the photocatalytic mechanism. On the other hand, changes in irradiation intensity significantly influenced the photolysis process, while photocatalysis was slightly affected, indicating that irradiation spectra are more relevant than intensity.

In this work, we report the effect of the addition of modifiers and network formers on the polaronic transport in iron phosphate glasses (IPG) in two systems of HfO 2 -B 2 O 3 -Fe 2 O 3 -P 2 O 5 , to which up to 8 mol% boron and hafnium are added. The addition of oxides significantly changes the Fe 2+ /Fe total ratio, thus directly affecting the polaron number density and consequently controlling DC conductivity trends for both series studied by impedance spectroscopy. Moreover, we found that short-range polaron dynamics are also under the influence of structural changes. Therefore, we have studied them in detail using model-free scaling procedures, Summerfield and Sidebottom scaling. An attempt to construct a super-master curve revealed that in addition to change in polaron number density, also the polaron hopping lengths change, and Sidebottom scaling yields a super-master curve. The spatial extent of the localized motion of polarons is correlated with polaron number density and two distinct regions are observed. A strong increase in the spatial extent of the polaron hopping jump could be related either to the structural changes due to the addition of HfO 2 and B 2 O 3 and their effects on the formation of polarons or to an inherent property of polaron transport in IP glasses with low polaron number density.