Nanometric Gold Oxide Particle Synthesis via Ascorbic Acid Reduction
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Solution Overview
Problem
Existing methods for producing gold (III) oxide require complex and expensive devices, multiple reagents, and strictly controlled conditions, making them inefficient and costly.
Innovation Solution
A method involving the mixing of HAuCl4 solution with ascorbic acid as a reducing agent, optionally with particle stabilizers, at controlled temperatures and stirring conditions to produce nanometric gold (III) oxide particles in a colloidal solution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If complex devices and strictly controlled conditions are used to produce gold (III) oxide, then the production reliability is improved, but the device complexity and manufacturing cost increase
Solution Approach 1:
The patent changes the chemical parameters of the reaction system by using HAuCl4 as a precursor and ascorbic acid as a reducing agent in aqueous solution, allowing gold oxide nanoparticle formation under mild, easily controllable conditions rather than requiring complex plasma or sputtering equipment
Solution Approach 2:
The patent replaces expensive, complex equipment (plasma generators, sputtering systems) with simple, inexpensive chemical reagents and basic laboratory glassware, making the production process accessible and cost-effective
2Manufacturing precision
If multiple reagents and strictly controlled conditions are used to produce gold (III) oxide, then the manufacturing precision is improved, but the ease of manufacture deteriorates
Solution Approach 1:
The patent achieves precise control of nanoparticle size (1-100 nm) by adjusting simple parameters such as ascorbic acid concentration, reaction temperature, and stirring rate, rather than requiring complex equipment controls
Solution Approach 2:
Ascorbic acid acts as an intermediary reducing agent that controllably reduces Au(III) to Au(0) and subsequently to gold oxide, providing a gentle and tunable reduction process that facilitates precise nanoparticle formation under mild conditions
3Stability of the object's composition
If complex equipment and multiple reagents are used to produce gold (III) oxide, then the product stability is improved, but the productivity and cost-effectiveness deteriorate
Solution Approach 1:
The patent employs ascorbic acid, which not only reduces the gold precursor but also stabilizes the formed nanoparticles through surface interaction, and the reaction system self-regulates to produce stable colloidal suspensions without requiring additional stabilization equipment or reagents
Solution Approach 2:
The patent achieves stable gold oxide nanoparticle formation by optimizing reaction parameters such as pH, temperature, and reagent ratios, resulting in colloidal solutions that remain stable for extended periods under simple storage conditions including light protection
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
Produces stable nanometric gold (III) oxide particles efficiently and cost-effectively without complex equipment, maintaining stability at room temperature for about a week and extending stability with light protection.
Implementation Method 1
mixing a precursor solution containing Au (III) ions in the form of HAuCl4 solution with a reducing agent in the form of ascorbic acid
Implementation Method 2
The obtained gold in zero oxidation state forms clusters which, due to their small size (below 1 nm, i.e. the critical size characteristic of nanoparticles), are metastable and undergo oxidation under the conditions of the carried out synthesis as the result of the reactions with the coexisting radicals
Implementation Method 3
optionally adding particle stabilizers and auxiliary substances
Data Source
Figure 1~2
AI summary
A method for producing nanometric gold (III) oxide particles is characterized in that 5-95 ml of an aqueous solution of L-ascorbic acid or D-ascorbic acid or L,D-ascorbic acid having a concentration of 2.0 ·10-4 - 9.0 ·10-3 mol/dm3 is added to 5-95 ml of HAuCl4 solution having a concentration of 1.0·10-4- 3.0·10-3 mol/dm3 and a temperature in the range of 10-100°C, and is stirred at 100-700 rpm for 10-60 minutes, and a temperature is maintained at 80-100°C, after which the resulting colloidal solution is cooled down to room temperature. Preferably, a steric particle stabilizer in the form of polyvinyl alcohol or polyvinyl pyrrolidone, in an amount of up to 5 g per 100 ml of solution, and optionally, chlorate salt in the form of NaClO4 or KClO4 in an amount of up to 0.1 g per 100 ml of solution, is added to the cooled colloidal solution and then is stirred until the stabilizer is completely dissolved.