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The effect of potassium chloride on BiVO4 morphology and photocatalysis

2021; Elsevier BV; Volume: 302; Linguagem: Inglês

10.1016/j.jssc.2021.122291

1095-726X

Sopheak Meng, Takaya Ogawa, Hideyuki Okumura, Keiichi N. Ishihara,

Catalytic Processes in Materials Science

The monoclinic BiVO 4 was synthesized via a facile one-pot hydrothermal synthesis . KCl concentration in the precursor greatly influences the crystal growth, morphology, and absorption properties of BiVO 4 attributed to the effect of Clˉ ions on the formation of BiOCl intermediate and preferential growth of BiVO 4 crystals along {010} planes. The photocatalytic property of BiVO 4 is accordingly altered based on the KCl content. The "shuriken-like" BiVO 4 prepared with 3 ​mmol of KCl exhibits the highest photocatalytic activity among our samples. Its photocatalytic rhodamine B degradation efficiency could reach 94.7% after 4 ​h of visible-light irradiation. The degradation efficiency only decreased to 90.8% after four runs of 4 h irradiation. The photodegradation rate with the shuriken-like BiVO 4 is around 2.3 times higher than that with the rod-like BiVO 4 prepared without KCl, owing to its highest relative intensity ratio of (040) to ( 1 ¯ 21 ) plane, which maximizes the exposed active {010} facets of BiVO 4 . Morphology of BiVO 4 can be altered by changing KCl concentration. Moreover, the KCl concentration also influences the photocatalytic activity of BiVO 4 (k/S BET , degradation rate constant (k) of rhodamine B over specific surface area (S BET ) of the sample) and the relative intensity ratio I ( 040 ) / I ( 1 ¯ 21 ) , related to the exposed {010} facets of BiVO 4 . • Shuriken-like BiVO 4 was synthesized using KCl (3 ​mmol) as a structure-directing agent in a hydrothermal method. • KCl concentration influenced the morphology, crystal structure, optical properties, and photocatalytic performance of BiVO 4 . • The shuriken-like BiVO 4 exhibited superior photocatalytic activity under visible light irradiation.