Bioinspired molecular co-catalysts bonded to a silicon photocathode for solar hydrogen evolution.

The production of fuels from sunlight represents one of the main challenges in the development of a sustainable energy system. Hydrogen is the simplest fuel to produce and although platinum and other noble metals are efficient catalysts for photoelectrochemical hydrogen evolution, earth-abundant alternatives are needed for large-scale use. We show that bioinspired molecular clusters based on molybdenum and sulphur evolve hydrogen at rates comparable to that of platinum. The incomplete cubane-like clusters (Mo(3)S(4)) efficiently catalyse the evolution of hydrogen when coupled to a p-type Si semiconductor that harvests red photons in the solar spectrum. The current densities at the reversible potential match the requirement of a photoelectrochemical hydrogen production system with a solar-to-hydrogen efficiency in excess of 10%. The experimental observations are supported by density functional theory calculations of the Mo(3)S(4) clusters adsorbed on the hydrogen-terminated Si(100) surface, providing insights into the nature of the active site.

Photocatalytic methane decomposition over vertically aligned transparent TiO2 nanotube arrays.

We report here on a study of vertically aligned TiO(2) nanotube arrays grown by the one-step anodic oxidation technique and their photocatalytic performance for methane decomposition. Quantitative activity data as a function of film thickness is obtained.

Screening of electrocatalytic materials for hydrogen evolution.

A general scheme for high-throughput screening of electrocatalysts is presented. By systematically exploiting a collection of theoretical and experimental materials databases, supplemented with quantum mechanical calculations, it locates systems that meet a set of pre-imposed selection criteria. As an example, the scheme is used to identify a binary "substrate-overlayer" electrocatalytic system for the hydrogen evolution reaction. The best catalysts found in this screening are based on Cu and W. The hydrogen evolution activity of W-Cu catalysts is evaluated by means of cyclic voltammetry. It turns out to be considerably more active than any of its constituents, pure W and Cu.

Synthesis, optical properties, and growth mechanism of blue-emitting CdSe nanorods.

Blue-emitting, cubic phase CdSe nanorods with an approximate diameter of 2.5 nm and lengths up to 12 nm have been synthesized at low temperature (100 degrees C) in a single surfactant using a single-source molecular precursor. Transmission electron microscopy and dynamic light scattering measurements indicate that the nanorods are formed from self-assembly of isotropic nanoclusters. Anisotropic growth in a single surfactant appears to be favored when growth occurs below the thermal decomposition temperature of the single-source precursor.