Reinforced concrete (RC) has been commonly used as a construction material for decades due to its high compressive strength and moderate tensile strength. However, these two properties of RC are frequently hampered by degradation. The main degradation processes in RC structures are carbonation and the corrosion of rebars. The scientific community is divided regarding the process by which carbonation causes structural damage. Some researchers suggest that carbonation weakens a structure and makes it prone to rebar corrosion, while others suggest that carbonation does not damage structures enough to cause rebar corrosion. This paper is a review of the research work carried out by different researchers on the carbonation and corrosion of RC structures. The process of carbonation and the factors that contribute to this process will be discussed, alongside recommendations for improving structures to decrease the carbonation process. The corrosion of rebars, damage to passive layers, volume expansion due to steel oxidation, and crack growth will also be discussed. Available protection methods for reducing carbonation, such as rebar structure coating, cathodic protection, and modifier implementation, will also be reviewed. The paper concludes by describing the most significant types of damage caused by carbonation, testing protocols, and mitigation against corrosion damage.

Biomedical implants are the need of this era due to the increase in number of accidents and follow-up surgeries. Different types of bone diseases such as osteoarthritis, osteomalacia, bone cancer, etc., are increasing globally. Mesoporous bioactive glass nanoparticles (MBGNs) are used in biomedical devices due to their osteointegration and bioactive properties. In this study, silver (Ag)- and strontium (Sr)-doped mesoporous bioactive glass nanoparticles (Ag-Sr MBGNs) were prepared by a modified Stöber process. In this method, Ag⁺ and Sr²⁺ were co-substituted in pure MBGNs to harvest the antibacterial properties of Ag ions, as well as pro-osteogenic potential of Sr² ions. The effect of the two-ion concentration on morphology, surface charge, composition, antibacterial ability, and in-vitro bioactivity was studied. Scanning electron microscopy (SEM), X-Ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) confirmed the doping of Sr and Ag in MBGNs. SEM and EDX analysis confirmed the spherical morphology and typical composition of MBGNs, respectively. The Ag-Sr MBGNs showed a strong antibacterial effect against Staphylococcus carnosus and Escherichia coli bacteria determined via turbidity and disc diffusion method. Moreover, the synthesized Ag-Sr MBGNs develop apatite-like crystals upon immersion in simulated body fluid (SBF), which suggested that the addition of Sr improved in vitro bioactivity. The Ag-Sr MBGNs synthesized in this study can be used for the preparation of scaffolds or as a filler material in the composite coatings for bone tissue engineering.

Recently, titania nanotubes (TNTs) have been extensively studied because both their functional properties and highly controllable morphology make them important building blocks for understanding nanoscale phenomena and realizing nanoscale devices. Compared with sol–gel and template-assisted methods, electrochemical anodization is a simple, cost-effective, and low-temperature technique offering additional advantages such as straightforward processing and ease of scale-up. This review focuses on the process modalities and underlying mechanism of electrochemical anodization to achieve a different set of TNTs for a variety of applications. Finally, important applications of TNTs are highlighted including biomedical devices, water purification, and solar cells.

Sugar industries generate substantial quantities of waste biomass after the extraction of sugar water from sugarcane stems, while biomass-derived porous carbon has currently received huge research attention for its sustainable application in energy storage systems. Hence, we have investigated waste sugarcane bagasse (WSB) as a cheap and potential source of porous carbon for supercapacitors. The electrochemical capacitive performance of WSB-derived carbon was further enhanced through hybridization with silicon dioxide (SiO₂) as a cost-effective pseudocapacitance material. Porous WSB-C/SiO₂ nanocomposites were prepared via the in situ pyrolysis of tetraethyl orthosilicate (TEOS)-modified WSB biomass. The morphological analysis confirms the pyrolytic growth of SiO₂ nanospheres on WSB-C. The electrochemical performance of WSB-C/SiO₂ nanocomposites was optimized by varying the SiO₂ content, using two different electrolytes. The capacitance of activated WSB-C was remarkably enhanced upon hybridization with SiO₂, while the nanocomposite electrode demonstrated superior specific capacitance in 6 M KOH electrolyte compared to neutral Na₂SO₄ electrolyte. A maximum specific capacitance of 362.3 F/g at 0.25 A/g was achieved for the WSB-C/SiO₂ 105 nanocomposite. The capacitance retention was slightly lower in nanocomposite electrodes (91.7–86.9%) than in pure WSB-C (97.4%) but still satisfactory. A symmetric WSB-C/SiO₂ 105//WSB-C/SiO₂ 105 supercapacitor was fabricated and achieved an energy density of 50.3 Wh kg⁻¹ at a power density of 250 W kg⁻¹, which is substantially higher than the WSB-C//WSB-C supercapacitor (22.1 Wh kg⁻¹).