PROCESS FOR DECOMPOSITION OF ORGANIC SYNTHETIC-DYES USING SEMICONDUCTOR-OXIDES NANOTUBES VIA DARK-CATALYSIS

摘要

In the present invention nanotubes-based dye-adsorbent powder is used for adsorption and decomposition of synthetic dye under dark-condition without the use of any external power-source such as the applied potential-difference, microwave, ultrasonicator, and others to save the energy consumption, which results in a complete dye-decomposition on the powder-surface. The surface-cleaned dye-adsorbent powder has very high specific surface-area and dye-adsorption capacity comparable with those of the original dye-adsorbent powder and can be recycled for the next cycles of dye-adsorption and dye-decomposition under the dark-condition. In the present method, the nanotubes-based dye-adsorbent powder is stirred under the dark-condition in an aqueous dye solution containing a strong oxidizer to get simultaneous dye-adsorption and dye-decomposition on the powder-surface, or getting dye adsorption in one solution and dye decomposition in a separate solution by said adsorbent powder under dark condition.

主权项

1. A process for decomposition of organic synthetic-dyes using semiconductor-oxides nanotubes via dark-catalysis which comprises the steps of:
(i) suspending nanotubes-based dye-adsorbent powder in an aqueous solution of organic synthetic-dye, (ii) adding a strong oxidizer in the above solution of step (i), stirring the suspension, under the dark-condition, using a magnetic or overhead stirrer for 10-3600 min for simultaneous dye-adsorption and dye-decomposition on the powder-surface; (iii) optionally transferring the dye adsorbent powder treated with solution of organic synthetic dye in step (i) to another aqueous solution containing a strong oxidizer and stirring the suspension, under the dark-condition, using a magnetic or overhead stirrer for 10-3600 min for the complete dye-decomposition on the powder-surface, (iii) separating the powder from the solution of step (ii) or step (iii) using a centrifuge operated at 2000-4000 rpm; (iv) drying the powder in an oven at 70-90° C. for 15-20 h; (v) recycling the dried-powder to repeat step-(i) to step-(iv) for the next cycle of dye-decomposition under the dark-condition