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Positively polarized gold nanoparticles have been demonstrated for use as stable olefin carriers for facilitated olefin transport membranes. The formation and size of gold nanoparticles stabilized by 4-dimethylaminopyridine (DMAP) were monitored using X-ray diffraction (XRD), transmission electron microscopy (TEM) and UV–visible spectroscopy. Nanocomposite membranes that deliver high separation performance for olefin/paraffin mixtures were prepared by dispersing gold nanoparticles stabilized by DMAP in a polymer matrix, poly(vinyl pyrrolidone) (PVP). X-ray photoelectron spectroscopy (XPS) and zeta potential measurements revealed that gold nanoparticles stabilized by DMAP exhibited a high positive polarity, which is responsible for the reversible interaction between the gold nanoparticles and olefin molecules. Compared to neat PVP membranes, the composite membranes consisting of PVP and the polarized gold nanoparticles showed stable and enhanced separation of olefin/paraffin mixtures. ; This work was supported by Energy Technology R&D program (2006-E-ID11-P-13) under the Korea Ministry of Commerce, Industry and Energy (MOCIE). KC acknowledges the financial support of NSI-NCRC and the Ministry of Education through the Brain Korea 21 Program at Seoul National University. This work was also supported by ERC Program of KOSEF grant funded by the Korea government(MEST) (R11-2005-048-00000-0).

Metal oxide semiconductor/chalcogenide quantum dot (QD) heterostructured photoanodes show photocurrent densities >30 mA/cm2 with ZnO, approaching the theoretical limits in photovoltaic (PV) cells. However, comparative performance has not been achieved with TiO2. Here, we applied a TiO2(B) surface passivation layer (SPL) on TiO2/QD (PbS and CdS) and achieved a photocurrent density of 34.59 mA/cm2 under AM 1.5G illumination for PV cells, the highest recorded to date. The SPL improves electron conductivity by increasing the density of surface states, facilitating multiple trapping/detrapping transport, and increasing the coordination number of TiO2 nanoparticles. This, along with impeded electron recombination, led to enhanced collection efficiency, which is a major factor for performance. Furthermore, SPL-treated TiO2/QD photoanodes were successfully exploited in photoelectrochemical water splitting cells, showing an excellent photocurrent density of 14.43 mA/cm2 at 0.82 V versus the Reversible Hydrogen Electrode (RHE). These results suggest a new promising strategy for the development of high-performance photoelectrochemical devices. ; Funding for open access charge: CRUE-Universitat Jaume I ; This work was supported by the Korea Center for Artificial Photosynthesis (KCAP) of Sogang University, funded by the Ministry of Science, ICT, and Future Planning (MSIP) through a National Research Foundation of Korea (Grant no. 2009-0093883). This work also was supported by a grant from the Basic Science Research Program through the National Research Foundation (NRF) of Korea funded by the Ministry of Science and ICT (NRF-2019R1A2C1003429) and by the Ministry of Education (NRF-2018R1A6A1A03024231). Also, this work was supported by the Ministerio de Ciencia, Innovacio′n y Universidades of Spain through the project ENE2017–85087-C3-1-R. Therefore, the authors acknowledge and thank the Korean and Spanish governments for technical and financial support. S. D. G.