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CdSe quantum dots combined with [FeFe] hydrogenase mimics as molecular catalytic reaction centers based on earth abundant elements have demonstrated promising activity for photocatalytic hydrogen generation. Direct linking of the [FeFe] hydrogenase mimics to the quantum dots surface is expected to enhance the activity of the system by establishing close contact between the [FeFe] hydrogenase mimics and the light harvesting quantum dots supporting the transfer and accumulation of several electrons which are needed to drive hydrogen evolution. To circumvent the problem of limited colloidal stability upon covalent functionalization of the quantum dots under optimal pH conditions for hydrogen evolution, in this work, we report on the functionalization of quantum dots immobilized in a thin film architecture on a substrate with [FeFe] hydrogenase mimics by covalent linking via carboxylate groups as anchoring functionality to bind to the QD surface. The functionalization was monitored via UV/Vis absorption, photoluminescence, infrared (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS) and quantified via micro X-ray fluorescence spectrometry (μXRF). The activity of the molecularly functionalized thin film was demonstrated and in dependence on the linker length TONs in the range of 360-580 (short linker) and 130-160 (long linker) were achieved. This work presents a proof of concept study showing the potential of thin film architectures of immobilized quantum dots as platform for light-driven hydrogen evolution and beyond.

Solar-driven photocatalytic generation of hydrogen from water is a potential source of clean and renewable fuel. Yet systems that are sufficiently stable and efficient for practical use have not been realized. Here, nanorod photocatalysts that have proven record activity for the water reduction half reaction were successfully combined with molecular metallocorroles suitable for catalyzing the accompanying oxidation reactions. Utilization of OH

The composition and atomic and electronic structure of a silicon nanowire (SiNW) array coated with tin oxide are studied at the spectromicroscopic level. SiNWs are covered from top to down with a wide bandgap tin oxide layer using a metal–organic chemical vapor deposition technique. Results obtained via scanning electron microscopy and X-ray diffraction showed that tin-oxide nanocrystals, 20 nm in size, form a continuous and highly developed surface with a complex phase composition responsible for the observed electronic structure transformation. The “one spot” combination, containing a chemically sensitive morphology and spectroscopic data, is examined via photoemission electron microscopy in the X-ray absorption near-edge structure spectroscopy (XANES) mode. The observed spectromicroscopy results showed that the entire SiNW surface is covered with a tin(IV) oxide layer and traces of tin(II) oxide and metallic tin phases. The deviation from stoichiometric SnO2 leads to the formation of the density of states sub-band in the atop tin oxide layer bandgap close to the bottom of the SnO2 conduction band. These observations open up the possibility of the precise surface electronic structures estimation using photo-electron microscopy in XANES mode.