| In this paper, the block-like and plate-like double-phased α/β-Ga2O3and theflower-like double-phased/-Ga2O3were prepared using Ga(NO3)3solution asGallium source and EDA as precipitation through hydrothermal treatment and thesubsequent calcination. The effects of preparing conditions on the crystal structuresand morphologies of the products were discussed, and the structures and performancestudies of them were carried out by taking advantages of XRD, SEM, BET, DRS, PLand UV-Vis technics. The experimental results are as follows:1. The block-like and the plate-like-Ga2O3were prepared respectively throughhydrothermal treatment and calcination process under different concentration of EDA,and double-phased α/β-Ga2O3with different compositions were obtained by thecalcination process of-Ga2O3at varied temperatures. It turned out that:-Ga2O3would transform gradually to-Ga2O3as temperature rose through the calcinationprogress, and the phase transformation of plate-like-Ga2O3was slower than that ofthe block-like-Ga2O3; the The absorption edge of the double-phased α/β-Ga2O3exhibited systematic blue shift with the increasing of the phase in both block-likeGa2O3and plate-like Ga2O3because the band gap of-Ga2O3was larger than-Ga2O3.PL patterns showed that PL emission intensities of the double-phased α/β-Ga2O3werestronger than the pure phases in both block-like Ga2O3and plate-like Ga2O3, thusoptical property of the double-phased Ga2O3was better. In degradation of RhodamineB, both the block-like and plate-like Ga2O3with different phase compositions showedgood photocatalytic performance, and the plate-like-Ga2O3performance better forthe80%above degradation on50mg/L RhB within30min, the catalytic activities firstdecreased then increased when there were more-Ga2O3in the double-phased Ga2O3.2. The flower-like-Ga2O3was prepared through hydrothermal treatment, and the flower-like double-phased/-Ga2O3possessing different compositions were producedby the calcination of it for2h in the range of500℃to800℃, which was larger thephase transformation of-Ga2O3to-Ga2O3. BET patterns showed that-Ga2O3produced directly from hydrothermal process possess big specific surface, whichwould decrease after calcination. The band gap size decreased in the order:-Ga2O3(non-calcination)>-Ga2O3>-Ga2O3(calcination), and the the absorption edge ofthe double-phased/-Ga2O3exhibited systematic blue shift with the-Ga2O3component increasing in the double-phased Ga2O3. PL pattern showed that-Ga2O3without calcination exhibited strong blue-green light emission, and the-Ga2O3aftercalcination exhibited blue and green mixed-light emission which was much weakerthan that of-Ga2O3without calcination, this would due to the crystal defects in theflower-like-Ga2O3prepared through hydrothermal treatment. Moreover, PL emissionintensity of the double-phased/-Ga2O3was stronger than that of pure phases, whichalso explained the optical property of the double-phased/-Ga2O3was better. Indegradation of Rhodamine B, the flower-like Ga2O3with different phase compositionsshowed excellent photocatalytic performance for the83%above degradation on50mg/L RhB within only20min, which was even better than the plate-like Ga2O3, thecatalytic activities increased when there were more-Ga2O3in the double-phasedGa2O3. |
