cellulose acetate or polyvinylpyrrolidone is electrospun into fibers having diameters of nanometer scale to form a first mat that is capable of absorbing hydrocarbons . a second mat may be formed from a solution of cellulose acetate or polyvinylpyrrolidone further containing tungsten trioxide . the solution is electrospun onto a copper mesh and then thermally oxidized to create a nanostructure comprising a grid or network of tungsten trioxide crystals and copper oxide crystals . the nanogrid is capable of photocatalyzing the degradation of hydrocarbons to carbon dioxide and water . the grid may be combined with the first mat to degrade hydrocarbons that the first mat absorbs .