Enhanced photocatalytic activity of MWCNT/TiO2 heterojunction photocatalysts obtained by microwave assisted synthesis

•TiO2–MWCNT composites were obtained using titanium butoxide by microwave synthesis.•Temperature control and pressure monitoring were used during the synthesis.•Composites were characterized by XRD, Raman, BET, SEM, TEM and UV–vis–DRS.•AB9 dye degradation in the order of 100% was reached with some composites.•The addition of 1 and 3 wt% of MWCNT to the TiO2 were obtained as an optimum region.

Herein reported are the synthesis and the photocatalytic activity of MWCNT/TiO2 heterojunction photocatalysts obtained by microwave-assisted method using titanium butoxide as precursor. The obtained materials were characterized by XRD, Raman, SEM, TEM, UV–vis, FTIR, surface area (BET) and photoluminescence. The characterization results showed that the addition of MWCNT did not provide structural changes on TiO2. The photocatalytic activities of the synthesized materials were investigated using acid blue 9 dye as a model molecule. The results indicate an enhancement on photocatalytic activity by the addition of low amount of MWCNT (1 and 3 wt%). The improvement is attained to the synergic effect between TiO2 and MWCNT which reduces the electron–hole pair recombination according with the photoluminescence study. In this way, a proposed schema for the enhanced photoactivity of the MWCNT/TiO2 heterojunction photocatalyst is discussed.

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