A high-potential porphyrin is codeposited on TiO 2 nanoparticles together with our Cp*-iridium water-oxidation catalyst to give a photoanode for a water-splitting cell. The photoanode optically resembles the porphyrin yet electrochemically responds like the Ir catalyst when it is immersed in aqueous solutions. Photoelectrochemical data show that illumination of the codeposited anode in water results in a marked enhancement and stability of the photocurrent, providing evidence for light-induced activation of the catalyst.Chart 1 Compounds 1 and 2.

A synergistic effect between anatase and rutile TiO2 is known, in which the addition of rutile can remarkably enhance the photocatalytic activity of anatase in the degradation of organic contaminants. In this study, mixed-phase TiO2 nanocomposites consisting of anatase and rutile nanoparticles (NPs) were prepared for use as photoanodes in dye-sensitized solar cells (DSSCs) and were characterized by using UV-vis spectroscopy, powder X-ray diffraction and scanning electron microscopy. The addition of 10-15% rutile significantly improved light harvesting and the overall solar conversion efficiency of anatase NPs in DSSCs. The underlying mechanism for the synergistic effect in DSSCs is now explored by using time-resolved terahertz spectroscopy. It is clearly demonstrated that photo-excited electrons injected into the rutile NPs can migrate to the conduction band of anatase NPs, enhancing the photocurrent and efficiency. Interfacial electron transfer from rutile to anatase, similar to that in heterogeneous photocatalysis, is proposed to account for the synergistic effect in DSSCs. Our results further suggest that the synergistic effect can be used to explain the beneficial effect of TiCl4 treatment on DSSC efficiency.

Efforts to improve the ease of assembly and robustness of photoanodes for light-driven water oxidation have led to the development of a modular assembly method for anchoring high-potential zinc porphyrins to TiO2 via coordination to surface-bound pyridine linkers. It is essential that the anchoring groups provide strong electronic coupling between the molecular dye and metal oxide surface for optimal electron injection and that they are robust under the operating conditions of the system. Here, four linker molecules functionalized with either carboxylate, phosphonate, acetylacetonate, or hydroxamate anchoring groups are compared for their relative water stability on TiO2. We also report the relative electron injection efficiencies, as measured by terahertz spectroscopy, for high-potential zinc porphyrins coordinated to TiO2 via pyridyl linkers with the series of anchoring groups.

Background Delayed-immediate breast reconstruction has traditionally involved placement of tissue expanders (TE) in the subpectoral (SP) position. Development of acellular dermal matrices has renewed interest in the prepectoral (PP) pocket, which avoids extensive muscle manipulation. We compare complication rates between PP and SP TE placement in autologous delayed-immediate breast reconstruction. Methods A retrospective chart review of patients undergoing autologous, delayed-immediate breast reconstruction at our institution (June 2009 to December 2018) was performed. Demographics, comorbidities, perioperative information, and complication incidence ≤12 months' follow-up were collected from first- and second-stage surgeries. Complications were modeled using univariable and multivariable binary logistic regressions. Results A total of 89 patients met the inclusion criteria, and data from 125 breast reconstructions were evaluated. Complication rates following TE placement trended lower in the PP cohort (28.8% vs 37%, P = 0.34). Overall complication rates following autologous reconstruction were significantly lower for PP reconstructions (7.7% vs 23.3%, P = 0.02). Multivariable regression showed TE position (P = 0.01) was a significant predictor of ≥1 complication following autologous reconstruction. Time delay between first- and second-stage surgeries was greater for SP reconstructions (199.7 vs 324.8 days, P < 0.001). Postoperative drains were removed earlier in the PP cohort (8.6 vs 12.0 days, P < 0.001). Mean follow-up time was 331.3 days. Conclusions Prepectoral reconstruction in the delayed-immediate autologous reconstruction patient leads to significantly lower complication rates, shorter duration between first- and second-stage surgeries, and shorter times before removal of breast drains compared with SP reconstructions.