Intercalated-Laurate-Enhanced Photocatalytic Activities of Ni/Cr-Layered Double Hydroxides

Laurate (LA−)-intercalated nickel–chromium-layered double hydroxides (LDHs) were synthesized using the co-precipitation method and investigated as a potential photocatalyst for methylene orange (MO) degradation. For comparison, series of LDHs with various molar ratios Ni2+(or Mg2+)/Cr3+(or Fe3+)/LA−(or CO32−) prepared. X−ray diffraction (XRD) element analysis showed that Ni/Cr(2/1)−1.0 LA LDH had most ordered crystal structure, same photocatalytic decolorization performance Mg/Cr(2/1)−1.0LA towards MO, which was significantly superior to Ni/Cr−CO3 LDH, Ni/Fe(2/1)−1.0LA LA−, Cr3+ LA−. The removal rate MO initial concentration 100 mg/L by Ni/Cr(2/1)−1.0LA (0.5 g/L) could be up 80% UV light irradiation 3 h, almost twice higher than sorption test. reaction in accordance pseudo-first-order kinetics, implied catalytic process took place on surface catalyst. All results indicate photodegradation Ni/Cr−LA enhanced onto intercalated LA− interlayer. free radical capture experiments suggest main role mechanism •O2− high oxidation activity produced electron-hole pairs excited light. Additionally, further reacted adjacent molecule pre-sorbed LA.