Electrochemical Preparation, Characterization And Application Of Several Micro/Nano Metal And Metal Oxide Functional Materials

Micro-nano materials are widely used in energy storage, biosensors, electroanalysis, surface-enhanced Raman scattering (SERS) spectroscopy, superhydrophobicity and solar energy conversion. Electrochemical methods can be used to synthesize nanowires, porous materials, and multi-layer micro-nano materials. Compared with other chemical methods, electrochemical synthesis of micro-nano materials has the advantage of low cost and high efficiency, and therefore are arousing widespread concern in the scientific research and industrial applications. The common electrochemical methods for preparation of micro-nano materials include electrodeposition, anodization, electrochemical dealloying, electrochemical oxidation reduction cycles (ORC), and so on.In this thesis, several novel and convenient electrochemical methods have been developed to prepare some functional metal and metal oxide micro-nano materials. Furthermore, SERS, photoelectrochemistry and wettability on these micro-nano structured materials have been investigated. The main contents of this thesis are summarized as follows:(1) Previous researches on the preparation of micro-nano structured materials via cathodic corrosion and anodization have been reviewed systemmtically.(2) Sb nanoparticles (NPs) have been prepared by dispersing a bulk antimony electrode under highly cathodic polarization both in TBAB acetonitrile solution and in aqueous NaOH solution at room temperature. Zintl ions Sbnx-seem to be involved in the cathodic dispersion processes in the two media.(3) Bimetallic BiSb NPs have been prepared by dispersing a bulk BiSb electrode under highly cathodic polarization both in TBAB acetonitrile solution and in aqueous NaOH solution at room temperature.(4) A green and facile one-step method has been developed to fabricate ultrathin nano-network gold films of low roughness via anodization of gold electrodes at the oxidation peak potential of an aqueous solution of L-ascorbic acid (AA) or hydroquinone (H2Q). The as-fabricated ultrathin nano-network gold films showed very strong SERS activity in comparison with the substrates prepared by some other electrochemical roughening methods.(5) Based on our previous researches, a one-step method has been developed to prepare micro-nanostructured tin monoxide (SnO) by potential-controlled anodic electrocrystallization in the prepassive electrodissolution region of Sn electrode in NaOH solutions. This method is facile and green without using any precursor salts and organic reagents in the solutions. The prepared SnO micro-nanostructures behaved superhydrophobicity without chemical modification.(6) Based on our previous researches, urchin-like Bi(OH)SO4·H2O films have been fabricated by anodization of bismuth in H2SO4solutions. This method is convenient and green, without using any precursor salts and organic reagents in the solutions. The urchin-like Bi(OH)SO4·H2O was used as the precursor to synthesize flower-like Bi2S3microstructures by anion exchange. The photocurrent response and wettability of the urchin-like Bi(OH)SO4·H2O and the flower-like Bi2S3films have also been investigated.