RESUMEN
3D-ordered porous CdS/AgI/ZnO nanostructures were designed to perform as high-performance photoelectrodes for photoelectrochemical (PEC) water-splitting applications. They rely on the advantages of an extremely large active surface area, high absorption capacity in the visible-light region, fast carrier separation and transportation caused by the intrinsic ladder-like band arrangement. These nanostructures were fabricated by employing a three-stage experiment in a sequence of hard mold-assisted electrochemical deposition, wet chemical method and deposition-precipitation. First, 3D-ordered ZnO nanostructures were electrochemically deposited using a polystyrene film as the sacrificed template. AgI nanoparticles were then decorated on the interfacial ZnO nanostructures by deposition-precipitation. Finally, these binary AgI/ZnO nanoporous networks were thoroughly wet-chemically coated with a CdS film to form a so-called 'ternary interfacial CdS/AgI/ZnO nanostructures'. The PEC water-splitting properties of the fabricated 3D nanostructures were systematically studied and compared. As a result, the highest efficiency of the fabricated 3D-ordered porous CdS/AgI/ZnO measured under the irradiation of solar simulation is about 5.2%, which is relatively 1.5, 3.5 and 11.3 times greater than that of the corresponding CdS/ZnO (3,4%), AgI/ZnO (1.5%) and pristine porous ZnO (0.46%) photoelectrodes, respectively. The significant improvement in the PEC activity is attributed to the enhanced charge separation and transport of ternary photoelectrodes caused by an unconventional ladder-like band arrangement formed between interfacial CdS-AgI-ZnO. Our study provides a promising strategy for developing such ternary photoelectrode generation that possesses higher stability and efficiency towards water-splitting processes.
RESUMEN
Three-dimensional (3D) cell culture systems are becoming increasingly popular due to their ability to mimic the complex process of angiogenesis in cancer, providing more accurate and physiologically relevant data than traditional two-dimensional (2D) cell culture systems. Microwell systems are particularly useful in this context as they provide a microenvironment that more closely resembles the in vivo environment than traditional microwells. Poly(ethylene glycol) (PEG) microwells are particularly advantageous due to their bio-inertness and the ability to tailor their material characteristics depending on the PEG molecular weight. Although there are several methods available for microwell fabrication, most of them are time-consuming and expensive. The current study utilizes a low-cost laser etching technique on poly(methyl methacrylate) materials followed by molding with PDMS to produce microwells. The optimal conditions for making concave microwells are an engraving parameter speed of 600 mm/s, power of 20%, and a design diameter of the microwell of 0.4 mm. The artificial tumor achieved its full size after 7 days of cell growth in a microwell system, and the cells developed drugs through a live/dead assay test. The results of the drug testing revealed that the IC50 value of zerumbone-loaded liposomes in HepG2 was 4.53 pM, which is greater than the IC50 value of zerumbone. The HepG2 cancer sphere's 3D platform for medication testing revealed that zerumbone-loaded liposomes were very effective at high doses. These findings generally imply that zerumbone-loaded liposomes have the capacity to target the liver and maintain medication delivery.