Efficient harnessing of solar energy presents a significant challenge in environmental cleanup efforts. This study develops a highly effective carbon quantum dots-modified hollow core-shell TiO 2 -LaFeO 3 heterojunction photocatalyst (CDs-TLFO). Structural analysis confirmed that nanosheets are loaded with CQDs, forming a hollow core-shell structure with intimate interconnection. Photocatalytic experiments reveal that CDs-TLFO degrads tetracycline hydrochloride (TC) 2.02 times faster than TLFO alone, and significantly outperformes h-TiO 2 and LaFeO 3 (11.28 and 2.78 times, respectively). This enhancement is attributed to CQDs acting as electron acceptors with upconversion properties, enhancing the separation of e – -h + pairs and boosting visible light absorption. Integration of CQDs onto the TLFO surface creates numerous active sites and enhances visible light absorption. SEM and TEM tests confirm that the catalyst has a hollow core-shell structure. ESR tests and radical trapping experiments indicate that the high degradation efficiency of the catalyst mainly owns to the synergistic effect of hydroxyl radicals (·OH) and superoxide radicals (·O 2 − ). The reusability and stability of the catalysts are investigated, potential TC degradation pathways are proposed as well as the photocatalytic reaction mechanism is revealed. This research introduces promising avenues for environmental cleanup and offers a straightforward, energy-efficient, and environmentally friendly method for producing CDs-TLFO heterojunction materials with superior photocatalytic capabilities.
Ensi Cao,Yixuan Zhang,Yongjia Zhang,Wentao Hao,Bing Sun,Li Sun
To enhance the acetone sensing capabilities of LaFeO 3 nanoparticles for practical applications in breath analysis, commercial n-type rutile TiO 2 nanoparticles were utilized as additives and directly mixed with LaFeO 3 nanoparticles synthesized via a sol–gel method. The obtained TiO 2 -LaFeO 3 nanocomposites were characterized by XRD, SEM, BET, and XPS. Compared to pure LaFeO 3 nanoparticles, the resulting TiO 2 -LaFeO 3 nanocomposites exhibited higher surface reactivity, as evidenced by their larger specific surface areas and higher oxygen vacancy contents. The introduction of TiO 2 also facilitated the formation of p-n heterojunctions, which enhanced the regulation of acetone molecules on internal carrier conduction within the nanocomposites. Therefore, the TiO 2 -LaFeO 3 nanocomposites demonstrated improved acetone sensing performance, including higher vapor response values, selectivity, and faster response/recovery speeds. Among the series of nanocomposites, those with an addition of 10 wt% TiO 2 exhibited the highest vapor response value (37.3 to 100 ppm) and the greatest selectivity against methanol and ethylene glycol at the prime operating temperature of 144 °C.