This article describes a simple and reliable approach to the fabrication of lauric acid (LA)-containing polystyrene (PS) nanofibers with LA/PS weight ratios up to 4 to 1 in the final dry mass of nanofibers. The obtained LAPS composite nanofibers achieved an unprecedented thermal energy storage capacity up to 78.4% of pristine LA because of the high LA loading as well as the lightweight and porous nature of the PS matrix. To the best of our knowledge, our result was higher than the previously reported values, which were generally less than 50%. The direct scanning electron microscopy (SEM) observation, IR spectra, Raman spectra, and differential scanning calorimeter (DSC) thermograms of LAPS nanofibers indicated that majority of LA was encapsulated inside the composite nanofibers. The X-ray diffraction (XRD) patterns showed that the crystal size of LA domains enlarged with the increase of LA loading in the composite nanofibers. In addition, the DSC run in T4P mode unveiled that the released latent heat during crystallization could raise the temperature of LAPS composite nanofibers above the onset temperature of crystallization, which was different from the reported results obtained from DSC run in traditional T1 mode. Furthermore, the undesirable supercooling effect was suppressed by increasing the percentage of LA in the composite nanofibers. Also, the LAPS composite nanofibers showed robust cycling stability and reusability during 100 continuous heating–cooling cycles in the temperature range of 0–80 °C. The LAPS composite nanofibers demonstrated excellent structural stability after solvent extraction and prolonged heat treatment. The entrapped LA was locked in the PS matrix without leaking out of the nanofibers even after continuous and repeated heating above the melting point of LA.

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This work demonstrates a facile method for the synthesis of a "green" photocatalyst for efficient solar degradation of toxic colorants in polluted water. CeO 2 nanofiber crystals were fabricated by electrospinning and thermal tuning at 500−1000 °C. It was found for the first time that the photocatalytic performance of pure CeO 2 was improved by simple thermal tuning. Without incorporating any potentially harmful impurities, the pure CeO 2 nanofiber crystals degraded up to 97.6% methylene blue (MB) in 180 min under simulated solar irradiation. Further, the CeO 2 nanofiber crystals demonstrated an excellent long-term recycling stability with less than 1% activity fluctuations in 10 cycles. The improved photocatalytic performance was attributed to the small crystal size, clean crystal surface, and plenty of oxygen vacancies of CeO 2 . SEM and TEM observations showed that the average fiber diameter decreased while the particle size increased with tuning temperature. FTIR revealed that the surface-adsorbed organic moieties decreased with the increase of temperature, making active sites more accessible for photocatalysis. The presence of oxygen vacancies was confirmed by both Raman and XPS, which were critical for the activation of oxygen in photocatalysis. Our pure CeO 2 photocatalyst is eco-friendly and inexpensive for large-scale application for the removal of toxic colorants to fulfill environmental sustainability.