Solid Solution Photocatalyst Bandgap Engineering for Odor Removal

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Solution Overview

Problem

Current photocatalysts, such as nano-titanium dioxide, have fixed conduction and valence band positions, limiting their ability to regulate light absorption wavelength and effectively address diverse odor-causing compounds, especially those requiring visible or UV light exposure.

Innovation Solution

A solid solution photocatalyst composition that regulates conduction and valence band positions and ranges, allowing absorption of light wavelengths from 10 nm to 14,000 nm, utilizing metal and non-metal oxides, sulfides, or nitrides, and incorporating a carrier and additives for enhanced deodorization and sterilization capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If common photocatalyst (nano-titanium dioxide) is used, then photocatalytic reaction can be produced, but the light wavelength absorption is limited to UV or visible light and cannot be regulated

Engineering Contradiction:
Improvelight wavelength absorption rangeVSAvoidphotocatalyst composition structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent uses composite semiconductor materials consisting of multiple elements (e.g., Cu-Zn-S-O-N system) to create a solid solution photocatalyst. This composite structure enables regulation of conduction and valence band positions through compositional control, allowing arbitrary adjustment of light absorption wavelength range while maintaining photocatalytic activity.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the compositional parameters of the semiconductor material by controlling the ratios of multiple elements (Cu, Zn, S, O, N) in the solid solution. By adjusting these parameters, the conduction and valence band positions can be regulated, thereby controlling the light wavelength absorption range to match different photocatalytic reaction requirements.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If fixed composition photocatalyst is used, then conduction and valence band positions are fixed, but cannot regulate absorption of light in different wavelength ranges

Engineering Contradiction:
Improveconduction and valence band position regulationVSAvoidphotocatalyst synthesis process
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent employs parameter changes by controlling the compositional ratios of multiple elements in the solid solution photocatalyst. By adjusting the concentrations of Cu, Zn, S, O, and N elements, the conduction and valence band positions can be precisely regulated to achieve desired light absorption characteristics for different photocatalytic applications.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a universal photocatalyst system that can perform multiple functions by adjusting its composition. The same base material system (Cu-Zn-S-O-N solid solution) can be tuned to absorb different wavelength ranges, making it applicable to various photocatalytic reactions including deodorization, sterilization, and organic matter decomposition under different lighting conditions.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Object-affected harmful factors

If deodorant releases air freshener or uses physical absorption, then stench can be covered up, but cannot effectively decompose stench compounds

Engineering Contradiction:
Improvestench compound removalVSAvoiddeodorant material consumption
Core Design Contradiction:
Object-affected harmful factorsVSLoss of substance

Solution Approach 1:

The patent utilizes the strong oxidizing capability of photogenerated holes and hydroxyl radicals produced by the photocatalyst under light irradiation. These strong oxidants directly decompose stench compounds (such as ammonia, amines, hydrogen sulfide, mercaptans, and short-chain fatty acids) into harmless substances like CO2, H2O, and nitrogen, achieving effective removal rather than mere masking.

Inventive Principle:
Principle #38Strong oxidants (Accelerated oxidation)

Solution Approach 2:

The photocatalyst material itself is not consumed during the deodorization process. It continuously absorbs light energy to generate photocatalytic reactions that decompose stench compounds, maintaining its catalytic activity without degradation. This self-service characteristic eliminates the need for frequent replacement or replenishment of the deodorant material.

Inventive Principle:
Principle #25Self-service

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 solid solution photocatalyst effectively removes a wide range of odorous compounds, including nitrogen and sulfur-containing substances, with a removal ratio exceeding 90%, offering improved environmental and recyclable solutions for deodorization and air purification.

Implementation Method 1

The solid solution photocatalyst composition utilizes its solid solution to regulate a conduction band position, a valence band position, a conduction band range and a valence band range of different photocatalytic reaction characteristics for removing the odorous substances

Methodology Applied
Scientific EffectPhotocatalysis: Photosynthesis

Implementation Method 2

when the nano-titanium dioxide photocatalyst exposed to light, it will produce photocatalytic reaction continuously, and produces a hydroxyl radical having function of decomposing organic matter

Methodology Applied
Scientific EffectPhoto-oxidation: Photo-oxidation

Data Source

PatentUS8932978B2Photocatalyst composition and preparation for the same
Publication Date: 2015.01.13 NATIONAL TSING HUA UNIVERSITY

AI summary

A solid solution photocatalyst composition and its preparation method are provided in the present invention. The solid solution photocatalyst can utilize its solid solution structure to regulate the conduction band position, valence band position, conduction band range and valence band range of the different response properties of the photocatalyst, so that oxidoreductive reaction is performed to remove the foul-smelling substances.