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Photocatalytic reduction of CO 2 to methanol over ZnFe 2 O 4 / TiO 2 (p–n) heterojunctions under visible light irradiation
Author(s) -
Iqbal Farukh,
Mumtaz Asad,
Shahabuddin Syed,
Abd Mutalib Mohamed Ibrahim,
Shaharun Maizatul Shima,
Nguyen Trinh Duy,
Khan Maksudur Rahman,
Abdullah Bawadi
Publication year - 2020
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.6408
Subject(s) - photocatalysis , methanol , heterojunction , annealing (glass) , materials science , hydrothermal circulation , selectivity , chemical engineering , nanotechnology , nuclear chemistry , catalysis , chemistry , optoelectronics , composite material , organic chemistry , engineering
BACKGROUND The development of visible light photocatalysts for CO 2 reduction into methanol is a challenge, as most of the reported photocatalysts can only work in a UV light environment. Slow kinetics and poor selectivity of CO 2 towards methanol are currently two significant drawbacks limiting the practical application of CO 2 reduction into methanol. RESULTS A ZnFe 2 O 4 /TiO 2 heterojunction with a ratio of unity was found to lead to the highest methanol yield of 693.31 μmol (g cat) −1 under a light intensity of 100 mW cm −2 . This photocatalyst also possessed the highest BET surface area of 6.5211 m 2 g −1 and better morphological structure, as compared with other ratios (1:2, 2:1 w/w). Interestingly, a loading of 1 g L −1 of ZnFe 2 O 4 /TiO 2 (1:1) heterojunction photocatalyst in the pre‐annealing treatment of ZnFe 2 O 4 at 900 °C and post‐annealing treatment of ZnFe 2 O 4 /TiO 2 (1:1) composite at 500 °C revealed that there was an enhancement in the interfacial interaction, and subsequently an efficient photoreduction of CO 2 into methanol. CONCLUSIONS This study demonstrates facile fabrication of p–n heterostructured phototcatalysts for reduction of CO 2 with marked improvement in methanol yield under visible light irradiation. It provides a viable route for exploring the effects of composition, hydrothermal treatment, and pre‐/post‐annealing treatment of hybrid semiconductor composites used to scale up photocatalytic CO 2 conversion in solar fuel‐based devices.