A zero-emission, closed-loop and hybrid solar-produced syngas power cycle is introduced utilizing an oxygen transport reactor (OTR). The fuel is syngas produced within the cycle. The separated oxygen inside the OTR through the ion transport membrane (ITM) is used in the syngas-oxygen combustion process in the permeate side of the OTR. The combustion products in the permeate side of the OTR are CO.sub.2 and H.sub.2O. The combustion gases are used in a turbine for power production and energy utilization then a condenser is used to separate H.sub.2O from CO.sub.2. CO.sub.2 is compressed to the feed side of the OTR. H.sub.2O is evaporated after separation from CO.sub.2 and fed to the feed side of the OTR.

Disclosed are methods and apparatuses for producing heavy water. In one embodiment, a catalyst is treated with high purity air or a mixture of gaseous nitrogen and oxygen with gaseous deuterium all together flowing over the catalyst to produce the heavy water. In an alternate embodiment, the deuterium is combusted to form the heavy water. In an alternate embodiment, gaseous deuterium and gaseous oxygen is flowed into a fuel cell to produce the heavy water. In various embodiments, the deuterium may be produced by a thermal decomposition and distillation process that involves heating solid lithium deuteride to form liquid lithium deuteride and then extracting the gaseous deuterium from the liquid lithium deuteride.

A zero-emission, closed-loop and hybrid solar-produced syngas power cycle is introduced utilizing an oxygen transport reactor (OTR). The fuel is syngas produced within the cycle. The separated oxygen inside the OTR through the ion transport membrane (ITM) is used in the syngas-oxygen combustion process in the permeate side of the OTR. The combustion products in the permeate side of the OTR are CO.sub.2 and H.sub.2O. The combustion gases are used in a turbine for power production and energy utilization then a condenser is used to separate H.sub.2O from CO.sub.2. CO.sub.2 is compressed to the feed side of the OTR. H.sub.2O is evaporated after separation from CO.sub.2 and fed to the feed side of the OTR.

Methods for the photoreduction of molecules are provided, the methods comprising illuminating an amino-terminated diamond surface comprising amino groups covalently bound to the surface of diamond with light comprising a wavelength sufficient to excite an electronic transition defined by the energy band structure of the amino-terminated diamond, thereby inducing the emission of electrons from the amino-terminated diamond surface into a sample comprising molecules to be reduced, wherein the emitted electrons induce the reduction of the molecules to form a reduction product; and collecting the reduction product.