Photoelectrodes of Al-doped La5Ti2Cu1−xAgxS5O7powder generate a photocathodic current attributable to the hydrogen evolution reaction at +0.7 Vvs.RHE.

A photoelectrochemical (PEC) cell composed of an Al‐doped La5Ti2Cu0.9Ag0.1S5O7 (Al‐LTCA) photocathode and a BaTaO2N (BTON) photoanode was employed for overall water splitting. The surface of the Al‐LTCA photocathode was modified first with CdS by a chemical bath treatment (CBT) and subsequently with TiO2 and Pt (to form Pt/TiO2/CBT‐CdS/Al‐LTCA). The modified photocathode Pt/TiO2/CBT‐CdS/Al‐LTCA showed a significantly enhanced photocurrent for the PEC hydrogen evolution reaction in strongly alkaline aqueous phosphate solutions. This enhancement was attributed to surface stabilization by TiO2 and to the enhanced charge separation caused by the formation of a p–n junction at the CBT‐CdS/Al‐LTCA interface. The BTON photoanode surface modified with Co and Ir species (Ir/Co/BTON) showed a lower onset potential than that of a Co‐loaded BTON photoanode for the PEC oxygen evolution reaction. A PEC cell incorporating the Pt/TiO2/CBT‐CdS/Al‐LTCA photocathode and the Ir/Co/BTON photoanode exhibited stoichiometric H2 and O2 generation. The solar‐to‐hydrogen energy conversion efficiency of this PEC cell was found to be 0.14 % following a minute of simulated sunlight irradiation.

ABSTRACT. Insulin-degrading enzyme (IDE) was detected by immunoblot analysis in highly purified rat liver peroxisomes. IDE in the peroxisomal fraction was resistant to proteolysis by trypsin and chymotrypsin under conditions where the peroxisomal membranes remained intact. After sonication of the peroxisomal fraction, IDE was recovered in the supernatant fraction. Further, the localization of IDE in the peroxisomes was shown by immunoelectron microscopy. In addition, IDE isolated from peroxisomes degraded insulin as well as oxidized lysozyme as a model substrate for oxidized proteins. These results suggest that IDE exists in an active form in the matrix of rat liver peroxisomes and is involved in elimination of oxidized proteins in peroxisomes.

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