Microstructures And Catalytic Properties Of Nanoporous Copper Oxides

Nanoporous copper oxides have wide application prospects due to their nanoporous structure,semiconductor properties and stable structure.In this paper,nanoporous copper with different micro-morphology was oxidized by thermal oxidation to prepare nanoporous copper oxides under different oxidation conditions.The phase composition and micro-morphology of nanoporous copper oxide were characterized to study the effects of microstructure on its electrocatalysis and photocatalytic properties.The results are shown as follows.Preparation of nanoporous copper oxides can control the synthesis of their phase and micro-morphology by changing the preparation conditions of nanoporous copper oxides.At the same time,the uniformity of the whole samples are ensured.In this paper,the average ligament size of nanoporous Cu/Cu2O is in the range of 157-345nm,the average ligament size of nanoporous Cu/Cu2O/CuO is in the range of 147-664nm,the average ligament size of nanoporous Cu2O/CuO is in the range of 214-607nm,and the average ligament size of nanoporous CuO is in the range of 598-667nm.It can be seen that the micro-morphology of nanoporous copper as the oxidation substrate has an important influence on the micro-morphology of nanoporous copper oxides.In the prepared nanoporous copper oxides,these crystallographic relationships show relatively lower lattice mismatch configuration for the phase interfaces.What’s more,the lower interfacial energy leads to better interfacial bonding,and the overall structure of the samples are more stable.The phase composition of the nanoporous copper oxides affects the catalytic performance of the nanoporous copper oxides for methanol.When the Cu(wt%)in the nanoporous copper oxides is higher than the content of other phases,the peak current density isin the range of 7.466 and 60.467mA·cm-2,When the content of Cu2O(wt%)in nanoporous copper oxide is higher than that in other phases,its peak current density is in the range of 0.019 and 0.457mA·cm-2,and when the content of CuO(wt%)in nanoporous copper oxide is higher than that in other phases,their peak current density is in the range of 0.086 and 0.364mA·cm-2.Thus,when the content of copper(wt%)in nanoporous copper oxides is the highest,the catalytic performance of nanoporous copper oxides for methanol is the best.It was found that the catalytic properties of nanoporous Cu/Cu2O and nanoporous Cu/Cu2O/CuO electrodes decrease with the increase of cycle times.With the increase of cycle times,the catalytic performance of nanoporous Cu2O/CuO and nanoporous CuO electrodes increase and then stabilize.It can be seen that the phase composition of nanoporous copper oxides has an important effect on their photocatalytic performance.After the same time of illumination,the degradation rates of Rhodamine B by nanoporous Cu/Cu2O,nanoporous Cu/Cu2O/CuO,nanoporous Cu2O/CuO and nanoporous CuO were all over 95%.The slopes of the dynamic fitting curves are 0.709,0.687,0.624 and 0.579 min-1,respectively.Degradation of Rhodamine B by nanoporous Copper oxides:nanoporous Cu/Cu2O>nanoporous Cu/Cu2O/CuO>nanoporous Cu2O/CuO>nanoporous CuO.