Unveiling Hierarchical Dendritic Co 3 O 4 -SnO 2 Heterostructure for Efficient Water Purification.

The construction of a desirable, environmentally friendly, and cost-effective nanoheterostructure photoanode to treat refractory organics is critical and challenging. Herein, we unveiled a hierarchical dendritic Co 3 O 4 -SnO 2 heterostructure via a sequential hydrothermal process. The time of the secondary hydrothermal process can control the size of the ultrathin SnO 2 nanosheets on the basis of the Ostwald solidification mass conservation principle. Ti/Co 3 O 4 -SnO 2 -168h with critical growth size demonstrated a photoelectrocatalysis degradation rate of ∼93.3% for a high dye concentrate of 90 mg/L with acceptable long-term cyclability and durability over reported Co 3 O 4 -based electrodes because of the large electrochemically active area, low charge transfer resistance, and high photocurrent intensity. To gain insight into the photoelectric synergy, we proposed a type-II heterojunction between Co 3 O 4 and SnO 2 , which prevents photogenerated carriers' recombination and improves the generation of dominant active species •O 2 - , 1 O 2 , and h + . This work uncovered the Ti/Co 3 O 4 -SnO 2 -168 as a promising catalyst and provided a simple and inexpensive assembly strategy to obtain binary integrated nanohybrids with targeted functionalities.