Inorganic Photochemistry

Weinstein, Julia A.

doi:10.1007/978-90-481-3830-2_3

Cited by 7 publications

(2 citation statements)

References 109 publications

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“…However, the excitation process by electron transfer can occur by direct transfer of the electron from the conduction band to substrates adsorbed on the surface of the catalyst; or indirect reduction by the formation of a radical product of the oxidation of organic molecules of low repulsion with the complex. Similarly, the presence of metals, such as Tl, Pb or Mn in solution has demonstrated their reductive ability of metals in solution [75].…”

Section: Photoreduction Of Metalsmentioning

confidence: 99%

Recent Developments in the Photocatalytic Treatment of Cyanide Wastewater: An Approach to Remediation and Recovery of Metals

et al. 2019

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For gold extraction, the most used extraction technique is the Merrill-Crow process, which uses lixiviants as sodium or potassium cyanide for gold leaching at alkaline conditions. The cyanide ion has an affinity not only for gold and silver, but for other metals in the ores, such as Al, Fe, Cu, Ni, Zn, and other toxic metals like Hg, As, Cr, Co, Pb, Sn, and Mn. After the extraction stage, the resulting wastewater is concentrated at alkaline conditions with concentrations up to 1000 ppm of metals. Photocatalysis is an advanced oxidation process (AOP) able to generate a photoreaction in the solid surface of a semiconductor activated by light. Although it is well known that photocatalytic processes can remove metals in solution, there are no compilations about the researches on photocatalytic removal of metals in wastewater with cyanide. Hence, this review comprises the existing applications of photocatalytic processes to remove metal and in some cases recover cyanide from recalcitrant wastewater from gold extraction. The use of this process, in general, requires the addition of several scavengers in order to force the mechanism to a pathway where the electrons can be transferred to the metal-cyanide matrices, or elsewhere the entire metallic cyanocomplex can be degraded by an oxidative pathway.

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Section: Photoreduction Of Metalsmentioning

confidence: 99%

Recent Developments in the Photocatalytic Treatment of Cyanide Wastewater: An Approach to Remediation and Recovery of Metals

et al. 2019

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“…Thermodynamically, the electron transfer for the HER is preferred to proceed through the LUMO of Re complexes in the electrochemical CO 2 reduction. However, the one‐electron‐transfer process from the electrodes to the Re complexes could be much faster than the HER process when considering J co is higher than J H2 . It means the electron transfer to Re complexes in the PEC CRR is kinetically preferred because of its low overpotential.…”

Section: Figurementioning

confidence: 99%

Photoelectrochemical CO₂ Reduction with a Rhenium Organometallic Redox Mediator at Semiconductor/Aqueous Liquid Junction Interfaces

et al. 2019

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Electrochemical and photoelectrochemical CO 2 reductions were carried out with Re(bh-bipy)(CO) 3 (OH 2 ) cocatalysts in aqueous electrolytes.C ompetition between hydrogen evolution and CO 2 reduction was observed under (photo)electrochemical conditions for both glassy carbon and CuInS 2 electrodes.T he partial current density for CO generation is limited even though the additional potential is applied. However,e lectrochemical hydrogen evolution was suppressed under photoelectrochemical conditions,and the selectivity and partial current density for CO were considerably increased when compared to the electrochemical reduction in an identical electrode/electrolyte system. This finding may provideinsights into using semiconductor/liquid junctions for solar fuel devices to overcome the limitations of electrolysis systems with an external bias.Artificial photosynthesis is the process wherein the CO 2 reduction reaction (CRR) takes place with hydrogen (water) and energy (sunlight) sources.T his process might be one of the key technologies for the future of human society because it is useful for producing valuable chemicals from waste contributing to global warming. [1] There are several ways to obtain solar fuel or chemicals by light irradiation, for example,photoelectrochemical cells (PECs) which are based on semiconductor/liquid junctions.I nt he PEC system, solar energy is directly converted into chemical energy at the semiconductor-electrolyte interface junction. Meanwhile,i n photovoltaic (PV) cell electrolysis systems,s olar energy is converted into electrical energy by photovoltaic cells,a nd then the electrical energy is used for electrochemical (EC) reactions. [2] Forb oth systems,i nput photons are finally converted into chemical energy forms.T herefore,t hese two different systems are not well distinguished.However,t he basic principles of PEC and PV-EC are clearly different. In particular,the electrode/electrolyte interface of aP EC is much different from that of EC reactions because of the properties of semiconductors.Unlike conducting electrodes,electron transfer between semiconductors and redox couples is limited, even though the Fermi level is shifted by applied potential due to rectifying properties of band pinning behavior. [3,4] When cocatalysts are combined with photoelectrodes,t herefore,t he energy structure between cocatalysts and semiconductor electrodes is more important than the one in the cocatalyst/non-semiconductor electrode system. In this research, we are reporting on different selectivities and reaction rates for PEC and EC systems having an identical cocatalyst, [(Re(bh-bipy)(CO) 3 (OH 2 )] + (bh-bipy = 4,4'-bis (hydroxymethyl)-2,2'-bipyridine), which is known to be very selective for CO production, using aC O 2 saturated aqueous electrolyte. [5] Firstly,t he CO 2 reaction was carried out with ag lassy carbon (GC) electrode in aC O 2 saturated electrolyte containing 1mm of the Re complexe (Figure 1a). From the linear sweep voltammetry (LSV) results,areduction peak of the Re complex is f...

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Photoelectrochemical CO₂ Reduction with a Rhenium Organometallic Redox Mediator at Semiconductor/Aqueous Liquid Junction Interfaces

et al. 2019

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Die Kontrolle der Selektivität zwischen H2‐Bildung und CO2‐Reduktion an der Grenzfläche eines Halbleiter/Elektrolyt‐Übergangs wird von O. S. Joo et al. in ihrer Zuschrift auf S. 16547 beschrieben. Eine Konkurrenz zwischen beiden Prozessen wurde an (Photo)elektroden unter elektrochemischen Bedingungen beobachtet, allerdings wurde die elektrochemische H2‐Bildung unter photoelektrochemischen Bedingungen, mit einem identischen Elektroden/Elektrolyt‐System, unterdrückt und eine hohe Selektivität für die CO2‐Reduktion gefunden.

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Inorganic Photochemistry

Cited by 7 publications

References 109 publications

Recent Developments in the Photocatalytic Treatment of Cyanide Wastewater: An Approach to Remediation and Recovery of Metals

Recent Developments in the Photocatalytic Treatment of Cyanide Wastewater: An Approach to Remediation and Recovery of Metals

Photoelectrochemical CO₂ Reduction with a Rhenium Organometallic Redox Mediator at Semiconductor/Aqueous Liquid Junction Interfaces

Photoelectrochemical CO₂ Reduction with a Rhenium Organometallic Redox Mediator at Semiconductor/Aqueous Liquid Junction Interfaces

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Inorganic Photochemistry

Cited by 7 publications

References 109 publications

Recent Developments in the Photocatalytic Treatment of Cyanide Wastewater: An Approach to Remediation and Recovery of Metals

Recent Developments in the Photocatalytic Treatment of Cyanide Wastewater: An Approach to Remediation and Recovery of Metals

Photoelectrochemical CO2 Reduction with a Rhenium Organometallic Redox Mediator at Semiconductor/Aqueous Liquid Junction Interfaces

Photoelectrochemical CO2 Reduction with a Rhenium Organometallic Redox Mediator at Semiconductor/Aqueous Liquid Junction Interfaces

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Photoelectrochemical CO₂ Reduction with a Rhenium Organometallic Redox Mediator at Semiconductor/Aqueous Liquid Junction Interfaces

Photoelectrochemical CO₂ Reduction with a Rhenium Organometallic Redox Mediator at Semiconductor/Aqueous Liquid Junction Interfaces