Green electrodeposition is a concept where electrodeposition is carried out sustainably; with safety, society, and environmental aspects playing a significant role in decision-making. ECS and electrochemists have seen large changes in the use of materials and chemicals over the last 50 years: for example, the slow phase out of mercury in labs and industry due to its toxicity [1]. On the other hand, the development of DSA and Boron-doped Diamond (BDD) electrodes have provided strategies for effluent control [2]. The Electrodeposition and Electroless Division (EDLP) members also would have faced challenges over the last 40 years. This could have involved replacing Cr(VI) electrolytes [3], Cd-based coatings, or developing cyanide-free processes [4]. In many cases EDLP has led the exploration of a new set of functional materials: an exemplar being “Get the Lead Out” Symposia Series focused on the development of Pb-free solders.

Green Electrodeposition is a marriage of Green Chemical Principles and Electrodeposition. Green Chemical Principles [5], urges one to focus on the reduction of waste, atom economy, energy efficiency, benign solvents, etc. These guidelines are useful for the development of any process, including electrodeposition processes. To adopt these principles, one has to understand and consider the stability of chemical formulations [6], surface electrochemistry that enables electrodeposition [7] and energy and atom efficiency of the process [8]. Electrochemistry, in particular, is a low temperature, low pressure process using electrons to drive reactions which reduces waste. It should therefore follow, that electrochemistry has a significant advantage in offering “Green” processes if developed, implemented and monitored carefully.

The talk will focus on how the concept started which simply focused on “prevention of generating” of waste. In particular it examined the notion of development of alternative formulations, the thermodynamics of stable electrolytes and associated issues. The application of this approach towards the development of gold deposition using non-cyanide baths for opto-electronic devices [9] will serve as an exemplar. Following this, the talk will focus effluent remediation of waste from printed circuit board manufacturing [10] and its extension to clean up of galvanic sludge from plating companies [11]. If time permits the use of engineering methodologies using current pulsing, novel agitation schemes and monitoring methods for energy efficiency and metal recycling and recovery will also be discussed.

References:

1. Castner-Kellner process as described in https://en.wikipedia.org/wiki/Castner%E2%80%93Kellner_process; Mercury poisoning – https://en.wikipedia.org/wiki/Mercury_poisoning. Accessed 07/04/2022.
2. Panniza, E. Brillas, C. Comninellis, J. Environ. Eng. Manage., 18(3), 139 (2008).
3. Liang, L. Ni, Q. Liu, J. Zhang, Surf. Coatings Tech., 218, 23 (2013).
4. Okinaka, M. Hoshino, Gold Bull, 31, 3 (1980); T. A. Green, Gold Bull. 40, 105 (2007).
5. https://www.acs.org/content/acs/en/greenchemistry/principles/12-principles-of-green-chemistry.html. Accessed 07/04/2022.
6. Green, A. E. Russell, S. Roy, J. Electrochem. Soc, 145, 875(1998).
7. Mattsson and J. M. Bockris, Trans. Faraday Soc., 55, 1586 (1959).
8. E. G. Hansal and M. Halmdienst, “Energy and Material Considerations”, Pulse Plating, 1^st Ed., pp. 184-188. Eds. W. Hansal and S. Roy, Leuze Verlag (2012).
9. J. Liew, S. Roy, K. Scott, Green Chemistry 5, 376 (2003).
10. Buckle and S. Roy, Separation and Purification Tech., 62, 86(2008); R. Buckle & S. Roy, 2006, ECS Transactions: Green Electrodeposition, 1, 13, pp. 53-58.
11. T. Huyen, T. D. Dang, M. T. Tung, N. T. T. Huyen, T. A. Green and S. Roy, Hydrometallurgy,164, 295 (2016).