Synthetic procedures of SiO2@mSiO2/Py-Si are shown in Scheme2. The target product was prepared via a reported
synthesis route with some modifications [27]. Py-Si and activated core–shell mesoporous silica (1:1mass ratio) were refluxed with anhydrous toluene for 48 h under an N2 atmosphere. The resulting product was collected by centrifugation and washed several times with ethanol. Finally, the product was dried in a vacuum oven.