Ca2+/Cr3+co-doped LaAlO3 infrared(IR)ceramics have been proven to be potential energy-saving materials for high-temperature industries because of their high emissivity and high-temperature stability.However,Cr6+formation commonly occurs in materials and poses environmental and health risks,such as Cr6+dissolution in water and CrO3(g)volatilization.In this study,we combined high emissivity with in situ detoxification by introducing residual Al2O3 into Ca2+/Cr3+co-doped LaAlO3 ceramics.Compared with the undoped ceramics,the addition of 20 wt%residual Al2O3 resulted in a 78.5%reduction to 18.44 mg/kg(lower than the EU standard of 20 mg/kg)in Cr6+dissolution and a decrease in 77.8%CrO3(g)volatilization.This significant detoxification effect can be attributed to the formation of CaAl12−xCrxO19.Additionally,as the residual Al2O3 content increased from 5 to 20 wt%,the ceramics maintained high emissivity,above 0.896 in the near-infrared band and 0.781 in the mid-infrared band.Furthermore,the IR coating effectively increased the surface temperature(from 767.1 to 790.7℃/min)and the heat radiation of the heating source,increasing the heating rate from 31.7 to 34.6℃/min during water heating.This work offers a promising approach for designing environmentally friendly IR ceramics with excellent IR performance for energy-saving applications in the high-temperature industry.
