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We have fabricated partially alignedfree-standing mesoporous pureanatase TiO2nanofiber mats (TiO2-NF) for photocatalysisby electrospinning on a rotating drum collector using a blend of titaniumisopropoxide (Ti(OiPr)4), with a carrierpolymer, polyvinylpyrrolidone (PVP) in acetic acid and ethanol. Calcinationremoves PVP and generates mesoporous TiO2-NF with fiberdiameters in the range of 25–75 nm by optimizing the electrospinningparameters such as electric field strength, polymer concentration,and flow rate of solution, etc. The band gap energyof TiO2nanofibers from the UV–vis absorption spectrais found to increase with an increase in the calcination temperature,thus allowing band gap engineering for different applications. Thesurface morphology, phase composition, crystallinity, surface area,and porosity of the TiO2-NF are also investigated. We demonstratethe efficient and reusable photocatalytic action of the partiallyaligned pure electrospun TiO2-NF and residual carbon containingTiO2-NF mats with an average fiber diameter ∼40nm in the photocatalytic degradation of a polycyclic aromatic hydrocarbon(PAH) dye, naphthalene. Small carbon residue (2.54%) containing TiO2-NF is found to be about twice as efficient as the pristineTiO2-NF in photodegradation of a PAH dye, but the effectivenessdeclined at higher carbon content. [ABSTRACT FROM AUTHOR]

Hydrogen is a notoriously difficult substance to store yet has endless energy applications. Thus, the study of long-term hydrogen storage, and high-pressure bulk hydrogen storage have been the subject of much research in the last several years. To create a research path forward, it is important to know what research has already been done, and what is already known about hydrogen storage. In this review, several approaches to hydrogen storage are addressed, including high-pressure storage, cryogenic liquid hydrogen storage, and metal hydride absorption. Challenges and advantages are offered based on reported research findings. Since the project looks closely at advanced manufacturing, techniques for the same are outlined as well. There are seven main categories into which most rapid prototyping styles fall. Each is briefly explained and illustrated as well as some generally accepted advantages and drawbacks to each style. An overview of hydrogen adsorption on metal hydrides, carbon fibers, and carbon nanotubes are presented. The hydrogen storage capacities of these materials are discussed as well as the differing conditions in which the adsorption was performed under. Concepts regarding storage shape and materials accompanied by smaller-scale advanced manufacturing options for hydrogen storage are also presented. [ABSTRACT FROM AUTHOR]