Non-contact thermometer for measuring surface temperature of photothermal catalysts using near-infrared black-body radiation spectrum

Electrons with energies higher than the thermal distribution, also known as hot electrons, can help reduce activation energy and improve selectivity in photothermal catalysis. To better understand this process, one needs to measure the non-thermal contributions, which requires accurately determining the catalysts' temperature. We present a non-contact optical technique for measuring the surface temperature of catalysts. This technique utilizes a spectrometer to measure the near-infrared (NIR) emission spectrum (950–1,600 nm). Since the measurement does not rely on black-body emission intensity alone, it does not suffer from temperature-dependent emissivity and other related issues. The NIR thermometer can achieve an accuracy of 1°C at 200°C and above. The use of NIR continuous spectral fitting can help understand non-thermal contributions in photothermal reactions and solve problems in fields where accurate high surface temperature measurement is required.