The sunlight active composite photocatalyst for water purification includes ZnO (zinc oxide) and Co.sub.3O.sub.4 (cobalt II, III oxide). The composite photocatalyst may, in the presence of natural sunlight, achieve complete mineralization of chemical and biological contaminants in water without leaving any hazardous by-products. The composite photocatalyst may be synthesized by a sol gel route or process.

The sunlight active composite photocatalyst for water purification includes ZnO (zinc oxide) and Co.sub.3O.sub.4 (cobalt II, III oxide). The composite photocatalyst may, in the presence of natural sunlight, achieve complete mineralization of chemical and biological contaminants in water without leaving any hazardous by-products. The composite photocatalyst may be synthesized by a sol gel route or process.

A photocatalytic composition is disclosed that includes a silver halide in combination with one or more rare earth elements. The composition may be used for the photocatalytic degradation of pollutants.

A photocatalytic composition is disclosed that includes a silver halide in combination with one or more rare earth elements. The composition may be used for the photocatalytic degradation of pollutants.

A system for generating a plasma discharge in liquid utilizes first and second electrodes spaced apart in an interior space of a vessel holding the liquid. A channel can be defined in certain embodiments at least partially by at least one of the first and second electrodes, and an inlet in fluid communication with the interior space is configured to generate a vortical fluid flow in the vessel. A method for generating a plasma discharge in liquid is also provided.

A system for generating a plasma discharge in liquid utilizes first and second electrodes spaced apart in an interior space of a vessel holding the liquid. A channel can be defined in certain embodiments at least partially by at least one of the first and second electrodes, and an inlet in fluid communication with the interior space is configured to generate a vortical fluid flow in the vessel. A method for generating a plasma discharge in liquid is also provided.

The present invention provides a method of suppressing larvae of barnacles in the settlement stage from settling on a substrate in water by irradiating light comprising the spectrum of 409 to 412 nm and a part of 400 to 460 nm to larvae of barnacles in the settlement stage in a direction from the substrate to the larvae of barnacles in the settlement stage.

The present invention provides a method of suppressing larvae of barnacles in the settlement stage from settling on a substrate in water by irradiating light comprising the spectrum of 409 to 412 nm and a part of 400 to 460 nm to larvae of barnacles in the settlement stage in a direction from the substrate to the larvae of barnacles in the settlement stage.

The present invention is a method of preventing settlement of a sessile organism on a structure in water, including irradiating light comprising the spectrum of 409 to 412 nm to the structure where settlement of the sessile organism is prevented.

The present invention is a method of preventing settlement of a sessile organism on a structure in water, including irradiating light comprising the spectrum of 409 to 412 nm to the structure where settlement of the sessile organism is prevented.