Development of CuO/Cu 4 (OH) 6 SO 4 Nanoparticle Mixtures to Optimize the H 2 S Adsorption.

In this paper, we report the H 2 S adsorption behavior of a sorbent composed of mixtures of tenorite (CuO) and brochantite [Cu 4 (OH) 6 SO 4 ]. These materials are readily prepared through the addition of NaOH (aq) to CuSO 4(aq) . They can be loaded onto polymer foams to create effective filters that can remove malodorous H 2 S gas, as evidenced by breakthrough tests. X-ray diffraction shows that the ratio of the two compounds in the mixture can be finely tuned by varying the amount of NaOH (aq) that is added to the reaction mixture. X-ray photoelectron spectroscopy shows that brochantite, like tenorite, has the ability to chemically adsorb H 2 S. Correlation of the H 2 S breakthrough data with scanning transmission electron microscopy measurements shows that the most effective sorbents contain nanoscale needle-like particles. These are likely to be formed largely by the tenorite phase. The samples with the greatest H 2 S adsorption efficacy contained less than 20% tenorite in the mixture, where these particles had the greatest abundance. The application of this sorbent onto porous substrates to create effective filters, along with the synthetic ease of its production, could allow this methodology to find use in a number of areas where H 2 S poses a problem. This could include areas where protective clothing is required to adsorb the gas from environments where there is a high level of H 2 S, for example, in wastewater treatment plants, oil and gas wells, or in the medical sector, where it could be deployed as filter media.