Copper Integrated Electrode for Nitrate Denitrification
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Solution Overview
Problem
Current electrocatalytic denitrification technologies face challenges in achieving nearly 100% 5-electron transfer reaction from NO3− to N2, leading to incomplete nitrate removal and toxicity issues due to the use of noble metals and strong reductants, which are costly and prone to deactivation.
Innovation Solution
A copper integrated electrode with a convertible oxidation state is developed, prepared using copper foam coated with graphene oxide and carbon, allowing for adjustable Cu2O morphology and electrochemical treatment, enabling efficient nitrate reduction to nitrogen with high selectivity without noble metals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If noble metals (Pd, Pt, Rh) and transition metals (Cu, Ni, Sn) are used as bimetallic electrocatalysts for nitrate reduction, then catalytic activity is improved, but cost increases and rapid deactivation occurs in water
Solution Approach 1:
The patent replaces expensive noble metals with copper foam, a much cheaper non-noble metal that can be easily obtained and processed. The copper foam serves as a disposable or regenerable electrode that maintains catalytic activity without the rapid deactivation issues of noble metals in water environments
Solution Approach 2:
The patent modifies the oxidation state of copper by treating the copper foam with alkali solutions to form Cu2O (copper(I) oxide) on the surface. This parameter change in oxidation state enhances the catalytic activity for nitrate reduction while maintaining stability in water, resolving the contradiction between activity and stability
2Productivity
If strong reductants such as zero-valent iron are used to achieve nitrate reduction, then reduction efficiency is improved, but 8-electron transfer reaction occurs causing significant decrease in N2 selectivity
Solution Approach 1:
The patent controls the oxidation state of copper by forming Cu2O on the copper foam surface through alkali treatment. This specific oxidation state parameter control enables the catalyst to favor the 5-electron transfer pathway that produces N2 with high selectivity, preventing the unwanted 8-electron transfer reaction that occurs with stronger reductants like zero-valent iron
3Productivity
If graphene oxide solution is used to cover copper foam surface, then electrocatalytic performance is improved, but preparation complexity increases
Solution Approach 1:
The patent applies graphene oxide solution to the copper foam surface as a preliminary treatment step before the alkali treatment. This preliminary action of coating the copper foam with graphene oxide enhances the electrocatalytic performance by providing a conductive carbon layer that facilitates electron transfer, while the overall process remains relatively simple and straightforward
Solution Approach 2:
The patent creates a composite structure by combining copper foam with graphene oxide coating, followed by alkali treatment to form Cu2O. This composite material approach integrates the advantages of copper (catalytic activity), graphene oxide (electrical conductivity and surface area), and Cu2O (controlled oxidation state for selective nitrate reduction), achieving high electrocatalytic performance
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The copper integrated electrode achieves nearly 100% denitrification and high nitrogen selectivity, maintaining cycle stability and reducing nitrate pollution effectively, using inexpensive and easily obtainable materials with simple preparation methods.
Implementation Method 1
a copper integrated electrode with a convertible oxidation state... the multi-electron transfer of nitrate reduction... by adjusting the content and morphology of Cu2O on the integrated electrode
Implementation Method 2
electrocatalytic denitrification technology... the 5-ETR to convert harmful NO3− into non-toxic and harmless nitrogen, N2... complex 5-electron transfer reaction (5-ETR)
Implementation Method 3
cutting copper foam into strips... covering a surface of the copper foam with a carbon layer... the prepared copper integrated electrode can be directly used
Data Source
AI summary
A copper integrated electrode with a convertible oxidation state, a preparation method and an application method are provided. The preparation process is based on an electrochemically induced self-growth method. Copper foam is used as a precursor, soaked in a graphene oxide solution, dried, calcined at high temperature and annealed, and then treated with an alkali solution to obtain the copper integrated electrode with the convertible oxidation state. The working electrode prepared by the nano-catalytic material of the present invention has good denitrification performance in the environmental field, which can achieve nearly 100% nitrate removal rate, nearly 100% nitrogen selectivity and long-term stability. These properties are due to the prepared working electrode having an oxidizable copper (I, II/0, I), oxygen vacancy (O) and a one-dimensional nanowire structure. The structure can regulate the adsorption and reduction of intermediate products, resulting in nearly 100% nitrate removal rate and nearly 100% nitrogen selectivity.