(180af) Development of Cu-BTC–TiO2 Composite for VOC Adsorption and Photocatalytic Degradation for Indoor Air Application

Volatile organic compounds (VOCs), such as formaldehyde, toluene, and benzene, are among the most common indoor air pollutants, originating from household products, furnishings, and building materials¹. These pollutants pose significant health risk due to their toxicity and long-term exposure effects, which include respiratory problems, allergic reactions, and even carcinogenic properties outcomes. As indoor air quality becomes a growing concern, the development of efficient materials for VOC capture and degradation has become increasingly important. In this context, metal-organic frameworks (MOFs) have emerged as promising materials due to their high surface areas, tunable porosity, and chemical functionalities. Cu-BTC (copper benzene-1,3,5-tricarboxylate), also known as HKUST-1, is a widely studied MOF that has demonstrated high gas adsorption performance owing to its porous crystalline structure^2,3. However, for photocatalytic activity required for the degradation of VOCs into less harmful products, its pure form has limitations. To overcome this challenge, recent research efforts have focused on the integration of MOFs with semiconducting metal oxides such as titanium dioxide (TiO₂), which is well-known for its photocatalytic activity under UV and visible light. The synergy between Cu-BTC and TiO₂ can potentially enable a bifunctional material that not only adsorbs VOCs efficiently but also catalytically decomposes them under suitable illumination, offering a sustainable solution for indoor air purification.

In the present work, we will present a composite material composed of Cu-BTC and TiO₂, targeting simultaneous adsorption and photocatalytic degradation of VOCs. The primary goal is to exploit the high surface area and VOC uptake potential of Cu-BTC with the photocatalytic functionality of TiO₂. The incorporation of TiO₂ nanoparticles into the Cu-BTC framework takes place through a post-synthetic or in-situ hybridization approach. To prevent charge recombination, graphene oxide has also been incorporated in the hybrid⁴. Different TiO₂ loadings and dispersion methods have been evaluated to optimize the interaction between the MOF and the photocatalyst. The composite has been tested for VOC adsorption capacity (e.g., using toluene or formaldehyde as model compounds) and photocatalytic degradation efficiency under UV and visible light in a controlled indoor air simulation environment. This work is expected to contribute toward the development of multifunctional MOF-based composites for advanced air purification systems, bridging the gap between adsorption and catalytic degradation in a single-step process.

Acknowledgement

The authors acknowledge financial support from Khalifa University through RIG-2024-052 and Center for Catalysis and Separation (CeCaS - RC2-2018-024) for lab support and instrumentation facilities.

References:

1. Rehman S, Zheng X, Aujla MI, Mehmood T. Recent advances in adsorptive removal of hazardous VOCs by metal-organic-framework-based materials. Chem Eng J. 2025;505:159257. doi:10.1016/J.CEJ.2025.159257
2. Varghese AM, Reddy KSK, Karanikolos GN. An In-Situ-Grown Cu-BTC Metal-Organic Framework / Graphene Oxide Hybrid Adsorbent for Selective Hydrogen Storage at Ambient Temperature. Ind Eng Chem Res. Published online 2021. doi:10.1021/ACS.IECR.1C04710/ASSET/IMAGES/LARGE/IE1C04710_0011.JPEG
3. Suh MP, Park HJ, Prasad TK, Lim DW. Hydrogen storage in metal-organic frameworks. Chem Rev. 2012;112(2):782-835. doi:10.1021/CR200274S/ASSET/CR200274S.FP.PNG_V03
4. Varghese AM, Reddy KSK, Bhoria N, Singh S, Pokhrel J, Karanikolos GN. Enhancing effect of UV activation of graphene oxide on carbon capture performance of metal-organic framework / graphene oxide hybrid adsorbents. Chem Eng J. 2021;420:129677. doi:10.1016/J.CEJ.2021.129677