Constituting fully integrated visual analysis system for Cu(II) on TiO₂/cellulose paper

Area of Science:

• Materials Science
• Environmental Chemistry
• Analytical Chemistry

Background:

• Cellulose filter paper is an abundant, low-cost porous material.
• Nanoscale titanium dioxide (TiO2) possesses unique catalytic and adsorptive properties.
• Developing integrated systems for simultaneous adsorption, photocatalysis, and sensing is crucial for environmental analysis.

Purpose of the Study:

• To develop a TiO2/cellulose paper (TCP) composite for efficient Cu(II) removal and detection.
• To investigate TCP's performance as an adsorbent, photocatalyst, and colorimetric sensor.
• To establish a visual, preconcentrated analytical method for Cu(II) in water samples.

Main Methods:

• Immobilization of nano-TiO2 onto cellulose filter paper to create TCP.
• Optimization of adsorption conditions (pH, temperature) for Cu(II).
• Colorimetric detection of Cu(II) using neocuproine indicator on TCP, quantified via image processing.
• Photodegradation of interfering humic substances.

Main Results:

• TCP demonstrated high adsorption capacity for Cu(II) (>1.65 mg) with >96.1% removal at pH 6.5 and 25 °C.
• Photodegradation effectively eliminated color interference from humic substances.
• A visual color change (white to orange) indicated Cu(II) presence.
• The system achieved a preconcentration factor of 10(4) for Cu(II) detection in drinking water and seawater.
• Detection limit of 0.073 μg L(-1) with a wide linear range (0.5-50.0 μg L(-1)).

Conclusions:

• TCP serves as a multifunctional material for simultaneous adsorption, photocatalysis, and colorimetric sensing of Cu(II).
• The integrated visual analysis system provides a sensitive and selective method for Cu(II) detection in environmental water.
• This approach offers a cost-effective and practical solution for water quality monitoring.