Controlled synthesis of Cu2O microcrystals in membrane dispersion reactor and comparative activity in heterogeneous Fenton application

摘要

A surfactant-free approach is proposed to fabricate various-shaped Cu2O particles with good uniformity by ceramic membrane dispersion. Glucose reduced cupric salt and precipitated Cu2O (dimension ca. 1 mu m and crystal size 18.5 nm) whose homogeneity was distinctly improved by distributing glucose solution through the ceramic mesoporous membrane. Particle shape including cube, sphere-like, octahedron and eight-pod was controlled kinetically by changing the concentration of sodium carbonate and sodium citrate with constant copper concentration. Morphologic transformation mechanism was studied with diffraction intensity ratio of (111)/(100) crystal planes. Micro-cubes formed at low pH and octahedral ones formed at high pH since crystal facet (111) is more stable than (100) with increased alkalinity. At the same pH, eight-pod grains were formed instead of cubes by adding citrate anions. Cu2O powders in octahedral shape was of the highest catalytic activity to degrade the organic pollutants in a heterogeneous Fenton reaction. CODs in an industrial pulp wastewater was eliminated from initial value 133 mg/L as low as to 26 mg/L Reduction rate of CODs in water by the octahedral Cu2O was 80% while the commercial Cu2O was only 30%. (C) 2018 Elsevier B.V. All rights reserved.