A pure-phase Cu2O film photocatalyst was successfully prepared by the electrodeposition technique from a non-pH-adjusted solution. To investigate the phase evolution and photocatalytic activity of the film, the electrodeposition was conducted at different deposition temperatures. Photocatalytic activity of the films was evaluated from methylene blue (MB) dye degradation. The Cu2O phase initially appeared at room temperature and its fraction was found to increase with increasing the deposition temperature, while the impurity phase was successfully diminished. A pure Cu2O film with a narrow optical bandgap energy of 1.96 eV was obtained at 75°C. The multi-faceted crystals were found to form at 45°C and became a truncated octahedral structure that possessed {111} and {100} facets as deposition temperature further increased. A preferred orientation growth of {110} facet, which is known to possess a relatively high surface energy, was produced at 75°C. The performance of MB photodegradation enhanced gradually by increasing the deposition temperature. The increase of photocatalytic activity could be attributed to the rise of photoelectrochemical response and the decrease of resistance charge transfer because of narrowing bandgap energy, increasing Cu2O fraction, and growing a relatively high catalytic activity facet which had escalated redox reaction that decomposed MB at the photocatalyst-solution interface.
The ubiquitous presence of pharmaceuticals and personal care products (PPCPs) in the environment has become a significant concern due to their persistence, bioaccumulation potential in biota, and diverse implications for human health and wildlife. This review provides an overview of the current state-of-the-art in environmental bioremediation techniques for reducing pharmaceutical residues, with a special emphasis on microbial physiological aspects. Numerous microorganisms, including algae, bacteria or fungi, can biodegrade various pharmaceutical compounds such as antibiotics, analgesics and beta-blockers. Some microorganisms are capable of transferring electrons within the cell, and this feature can be harnessed using Bio Electrochemical Systems (BES) to potentiate the degradation of pharmaceuticals present in wastewater. Moreover, researchers are evaluating the genetic modification of microbial strains to improve their degradation capacity and expand list of target compounds. This includes also discuss how environment changes, such as fluctuations in temperature or pH, may affect bioremediation efficiency. Furthermore, the presence of pharmaceuticals in the environment is emphasised as a major public health issue because it increases the chance for antibiotic-resistant bacteria emerging. This review combines existing information and outlines needed research areas for improving bioremediation technologies in the future.