"Textured" Metal Oxide Nanofilms

The official website of the US Brown University released an announcement on the 7th that researchers from the School of Engineering used the graphene template they created to successfully synthesize ultra-thin metal oxide nanostructures with wrinkled and pitted structures, and demonstrated that these weave structures can be significant. Improve photocatalyst and battery electrode performance. Related research was published in the Journal of the American Chemical Society's "Nano".

The research team had previously successfully introduced creases and pits on graphene oxide monolayer nanomaterials, which greatly enhanced the water resistance and conductivity of graphene. But they wanted to use the same method to enhance the performance of metal oxides and other materials but encountered difficulties: the introduction of pleated structures requires multiple pressures on the graphene from multiple directions, and the metal oxides are too hard. Broken, unable to operate. "So, we tried to use a wrinkled graphene layer as a template, resulting in a wrinkled metal oxide film," said Chen Boyan, a postdoctoral researcher who led the study.

Chen Boyan's team deposited graphene on a heat-shrinkable polymer bottom layer. During the shrinkage process, the bottom layer squeezes graphene to the top layer, forming a wrinkled or pitted structure. They then remove the bottom layer, leave a vacant layer beneath the graphene fold layer, and place the wrinkled graphene layer in a positively charged aqueous metal ion solution. The negatively charged graphene will attract the metal ions to the interlayer vacancy, where they synthesize the same wrinkled or pitted structure as the graphene layer, and finally oxidize and volatilize the graphene, leaving a wrinkled metal oxide layer.

They used this graphene template to make complex structures of different metal oxides such as zinc, aluminum, magnesium, and copper. Due to the graphene compression process, multiple pressures can be applied in multiple directions to obtain different pleat structures.

Tests have shown that the new structure of the wrinkled surface can enhance the properties of metal oxides, such as wrinkled magnesia electrode conductivity is 4 times that of the flat layer, the cleavage of zinc oxide photocatalytic reaction catalytic performance is also flat 4 times. Chen Boyan said that the new method can be used not only to improve the properties of metal oxides, but also to develop super thin films with different properties and new two-dimensional materials. (Reporter Nie Cuirong)