“Organic Aqua Regia”—Powerful Liquids for Dissolving Noble Metals

Lin, Wei; Zhang, Rongwei; Jang, Seung-Soon; Wong, Ching-Ping; Hong, Jungil

doi:10.1002/ange.201001244

Cited by 33 publications

(15 citation statements)

References 25 publications

(14 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Lin and co-workers [68] have recently formulated etchants consisting of mixtures of thionyl chloride (SOCl 2 ) and organic solvents such as pyridine and N,N-dimethyl formamide (DMF). Such formulations that can etch gold at moderate rates and have been referred to as 'organic aqua regia'.…”

Section: Nonaqueous Etchantsmentioning

confidence: 99%

“…In terms of Fig. 13 Probable reaction scheme for the dissolution of gold in SOCl 2 /pyridine mixtures ('organic aqua regia') [68] addressing environmental and safety concerns, the iodinebased non-aqueous etchants [66] seem to be the most appropriate. Issues regarding the cost of materials and environmental disposal will also need to be considered before any of these etchants can be adopted.…”

Section: Nonaqueous Etchantsmentioning

confidence: 99%

See 1 more Smart Citation

Gold etching for microfabrication

2014

View full text Add to dashboard Cite

The etching of gold is a key enabling technology in the fabrication of many microdevices and is widely used in the electronic, optoelectronic and microelectromechanical systems (MEMS) industries. In this review, we examine some of the available methods for patterning gold thin films using dry and wet etching techniques. Dry methods which utilise reactive ion etching (RIE) have a number of important advantages over other methods, but the low volatility of gold etch products has made the development of suitable processes problematic. More recently, the adoption of high-density plasma reactors with optimised chlorine-based chemistries has allowed improved processes to be developed, and etching in hydrogen plasmas also shows promise. Wet etching methods for gold have also been critically reviewed. Traditionally, iodine-and cyanide-based etch processes have been used, but in the last decade, a number of alternative etchants have been studied. Of particular interest is the recent development of a range of novel nonaqueous-based gold etchants, and the suitability of these etchants for microfabrication is assessed.

show abstract

Section: Nonaqueous Etchantsmentioning

confidence: 99%

Section: Nonaqueous Etchantsmentioning

confidence: 99%

Gold etching for microfabrication

2014

View full text Add to dashboard Cite

show abstract

“…As a further example, mixtures of thionyl chloride and organic solvents/reagents such as pyridine, N,N-dimethylformamide and imidazole, named organic aqua-regia, have aroused great interest in their capability to dissolve gold and other noble metals with high dissolution rates under mild conditions [6]. This method was applied for etching Au metallization on a circuit board.…”

Section: Introductionmentioning

confidence: 99%

From trash to resource: a green approach to noble-metals dissolution and recovery

Serpe

Artizzu²,

Espa³

et al. 2014

Green Processing and Synthesis

View full text Add to dashboard Cite

Abstract:A process based on the lixiviant properties of organic mixtures of dihalogen/S,S-ligands, N,N′-dimethylperhydrodiazepine-2,3-dithione (Me 2 dazdt) and tetraalkylthiuramdisulphide (Et 4 TDS) in the presence of diiodine, for gold recovery from the non-ferrous metal fraction of real shredded waste electric and electronic equipment (WEEE), is presented here. Selective dissolution of metals is achieved through a sequence of three steps where the oxidation of different kinds of metals is achieved by using: (1) refluxing water solutions of HCl 1:5 under Ar atmosphere (Sn, Zn, etc.); (2) water solutions of NH 3 /(NH 4 ) 2 SO 4 mixtures in the presence of H 2 O 2 on the resting sample (Cu, Ag); and (3) acetone solutions of Me 2 dazdt or Et 4 TDS/ I 2 mixtures on the final residue (Au). Each step is followed by a further treatment for: (1) metal recovery, in the case of Au, Cu, Ag; and (2) inertization, in the case of heavy metals. As a whole, the process is very promising for effective recovery of gold and other valuable noble-metals and for using non harmful reagents in mild conditions.

show abstract

“…Therefore, a breakthrough in the chemistry of Pt recycling is needed for the whole process to become safer, more economical, sustainable and environmentally friendly. Interestingly, a few recent reports showed novel approaches based on organic solvents17 and ionic liquids18 for enhanced Pt dissolution. However, their environmental sustainability, economic viability and real industry compatibility is questionable.…”

mentioning

confidence: 99%

Platinum recycling going green via induced surface potential alteration enabling fast and efficient dissolution

et al. 2016

View full text Add to dashboard Cite

The recycling of precious metals, for example, platinum, is an essential aspect of sustainability for the modern industry and energy sectors. However, due to its resistance to corrosion, platinum-leaching techniques rely on high reagent consumption and hazardous processes, for example, boiling aqua regia; a mixture of concentrated nitric and hydrochloric acid. Here we demonstrate that complete dissolution of metallic platinum can be achieved by induced surface potential alteration, an ‘electrode-less' process utilizing alternatively oxidative and reductive gases. This concept for platinum recycling exploits the so-called transient dissolution mechanism, triggered by a repetitive change in platinum surface oxidation state, without using any external electric current or electrodes. The effective performance in non-toxic low-concentrated acid and at room temperature is a strong benefit of this approach, potentially rendering recycling of industrial catalysts, including but not limited to platinum-based systems, more sustainable.

show abstract

“Organic Aqua Regia”—Powerful Liquids for Dissolving Noble Metals

Cited by 33 publications

References 25 publications

Gold etching for microfabrication

Gold etching for microfabrication

From trash to resource: a green approach to noble-metals dissolution and recovery

Platinum recycling going green via induced surface potential alteration enabling fast and efficient dissolution

Contact Info

Product

Resources

About