Spontaneous Generation of H₂O₂ and Hydroxyl Radical through O₂ Reduction on Copper Phosphide under Ambient Aqueous Condition

Abstract

Copper phosphide (Cu x P) was synthesized and tested for its reactivity for generating H2O2 through spontaneous reduction of dioxygen under ambient aqueous condition. The in situ generated H2O2 was subsequently decomposed to generate OH radicals, which enabled the degradation of organic compounds in water. The oxygen reduction reaction proceeded along with the concurrent oxidation of phosphide to phosphate, then copper ions and phosphate ions were dissolved out during the reaction. The reactivity of Cu x P was gradually reduced during 10 cycles with consuming 8.7 mg of Cu x P for the successive removal of 17 μmol 4-chlorophenol. CoP which was compared as a control sample under the same experimental condition also produced H2O2 through activating dioxygen but did not degrade organic compounds at all. The electrochemical analysis for the electron transfers on Cu x P and CoP showed that the number of electrons transferred to O2 is 3 and 2, respectively, which explains why OH radical is generated on Cu x P, not on CoP. The Cu+ species generated on the Cu x P surface can participate in Fenton-like reaction with in situ generated H2O2. Cu x P is proposed as a solid reagent that can activate dioxygen to generate reactive oxygen species in ambient aqueous condition, which is more facile to handle and store than liquid/gas reagents (e.g., H2O2, Cl2, O3).

Carbon nitride nanotubes with in situ grafted hydroxyl groups for highly efficient spontaneous H2O2 production

“…(3)-(6) [15,21]. The photocatalytic production of H2O2 eventually reaches a steady-state maximum level due to the competition between reductive formation and subsequent oxidative loss pathways [21][22][23][24]. However, to the best of our knowledge, few studies have been focused on enhancing H2O2 production by suppressing the various decomposition reactions.…”

Defects on CoS2−x: Tuning Redox Reactions for Sustainable Degradation of Organic Pollutants

“…were considered as good oxygen‐activating reagents, which had strong reducibility for the reduction and activation of O 2 to H 2 O 2 [6] . Very recently, as a catalyst originally used for hydrogen production, CuP x was reported to achieve the in situ generation and activation of H 2 O 2 through a three‐electron process, among which phosphorus ions provided electrons for activating O 2 , and Cu I acted as a catalyst for activating H 2 O 2 [7] . However, electrocatalysis has high energy consumption, and it is not suitable for controlling large area river pollution.…”

“…OH. Thus, there are two possible reasons for the gradual inactivation of CuP x : (1) CuP x was continuously consumed as a reagent in the reaction; (2) copper phosphate may be deposited in situ on the CuP x surface, although the remaining CuP x retained the oxidation state of copper and phosphorus (Figure S13) [7] . Especially, the CoS 2 ‐1.5 h/Fe 2+ system achieved a high total organic carbon (TOC) removal rate of 70.7 %.…”

“…[6] Very recently, as a catalyst originally used for hydrogen production, CuP x was reported to achieve the in situ generation and activation of H 2 O 2 through a three-electron process, among which phosphorus ions provided electrons for activating O 2 , and Cu I acted as a catalyst for activating H 2 O 2 . [7] However, electrocatalysis has high energy consumption, and it is not suitable for controlling large area river pollution. Although photocatalysis is green and environmentally friendly, the solar light penetration is limited and large-scale industrial promotion cannot be realized.…”

Facile Synthesis of CuO Nanosheets and Efficient Degradation of Rhodamine B in a Copper Oxide/Ascorbic Acid/Hydrogen Peroxide System: Kinetics, Fate of Ascorbic Acid, and Mechanism

“…A Cu‐doped AlPO 4 framework was found to display effective Fenton‐like activity for bisphenol A (BPA) degradation, which was attributed to the cycle of Cu(I) and phenoxo‐Cu(II) complexes formed during the interaction of Cu‐AlPO 4 , BPA and H 2 O 2 . Additionally, hydroxylamine was used as a reducing agent of M (n+1)+ to facilitate the regeneration of M n+ ; however, hydroxylamine is highly toxic and not suitable to be used in water treatment . Therefore, acceleration of the M (n+1)+ /M n+ cycle is an effective strategy for the development of environmentally friendly and heterogeneous Fenton catalysts with high activity.…”