Walter Marte

Direct electrochemical reduction of indigo

Reducing agents required in the dyeing process for vat and sulfur dyes cannot be recycled, and lead to problematic waste products. Therefore, modern economical and ecological requirements are not fulfilled. The application of direct electrochemical reduction of indigo as a novel route has been investigated by spectrophotometric and voltammetric experiments in laboratory cells. Experiments yield information about the reaction mechanism and the kinetics, and they show the possibility of this new route for production of water-soluble indigo, which offers tremendous environmental benefits.

Electrocatalytic hydrogenation of vat dyes

Increasing eco-efficiency of textile wet processes has become an important topic. Reducing agents required for the application of vat dyes (i.e. indigo) cannot be recycled, and lead to problematic waste products. Therefore, modern economical and ecological requirements are not fullfilled. The application of electrocatalytic hydrogenation of vat dyes at electrodes comprising a thin grid coated with a layer of nickel in which fine particles of Raney nickel are dispersed has been investigated by spectrophotometric and voltammetric experiments in laboratory cells. Experiments show the feasibility of this new route which offers tremendous environmental benefits and has a vast potential in textile dyeing processes, because it does not require any reducing agent.