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The interfacial contact between TiO 2 and graphitic carbon in a hybrid composite plays a critical role in electron transfer behavior, and in turn, its photocatalytic efficiency. Herein, we report a new approach for improving the interfacial contact and delaying charge carrier recombination in the hybrid by wrapping short single-wall carbon nanotubes (SWCNTs) on TiO 2 particles (100 nm) via a hydration-condensation technique. Short SWCNTs with an average length of 125 ± 90 nm were obtained from an ultrasonication-assisted cutting process of pristine SWCNTs (1–3 μm in length). In comparison to conventional TiO 2 –SWCNT composites synthesized from long SWCNTs (1.2 ± 0.7 μm), TiO 2 wrapped with short SWCNTs showed longer lifetimes of photogenerated electrons and holes, as well as a superior photocatalytic activity in the gas-phase degradation of acetaldehyde. In addition, upon comparison with a TiO 2 –nanographene “quasi-core–shell” structure, TiO 2 -short SWCNT structures offer better electron-capturing efficiency and slightly higher photocatalytic performance, revealing the impact of the dimensions of graphitic structures on the interfacial transfer of electrons and light penetration to TiO 2 . The engineering of the TiO 2 –SWCNT structure is expected to benefit photocatalytic degradation of other volatile organic compounds, and provide alternative pathways to further improve the efficiency of other carbon-based photocatalysts. 

Nanosized, well-dispersed titania particles were synthesized via a hydrothermal method using multiwalled carbon nanotubes (MWCNTs) as structural modifiers during the nucleation process to decrease aggregation. Synthesized TiO 2 /MWCNT composites containing different amounts of MWCNTs were characterized using N 2 physisorption, XRD, spectroscopic techniques (Raman, UV-visible, and X-ray photoelectron), and electron microscopy to illuminate the morphology, crystal structure, and surface chemistry of the composites. Photocatalytic performance was evaluated by measuring the degradation of acetaldehyde in a batch reactor under UV illumination. Average rate constants decrease in the following order: TiO 2 /MWCNT-1% > TiO 2 > TiO 2 /MWCNT-5%. Addition of MWCNTs beyond the optimum loading ratio of 1:100 (MWCNT:TiO 2 ) diminishes the effectiveness of the photocatalyst and the synergistic effect between MWCNTs and TiO 2 . The primary mechanism for photocatalytic activity enhancement in TiO 2 /MWCNT-1% is thought to be due to increased porosity, hydroxyl enrichment on the surface, and high dispersion of TiO 2 particles.