Unless otherwise stated, the CO2 adsorption step was conducted for 15 min, followed by 5 min of bulk heat using an oil bath at 110 °C, or 5 min of localized heat using LEDs. Low-power LEDs from ThorLabs were mainly used for this study, including 625 nm (red light), 385 nm (UV light), and a broadband white light, with maximum input current of 1,000 mA, 700 mA, and 1,000 mA, respectively. Their emission spectra can be found in Figure . A focusing lens was attached to the LEDs whose focal length is 20 cm from the LED. The light was focused to a ~1 cm diameter circle on one side of the flat piece of contactor. Using a Thorlabs wireless power meter PM160T, we measured the irradiances at different set currents for the monochromatic LEDs and summarized the results in Table . Because PEI starts experiencing thermal degradation at 120-135 °C in dry conditions, it is crucial to keep the composite below this temperature to ensure compatibility of plasmonic heating induced by the light-activation of TiN with the aminopolymer. To this end, the temperature profiles of illuminated TiN at different set currents to obtain different irradiances, as shown in Figure and Table , using a FLIR E6 infrared (IR) camera. When a low irradiance is used, 10 mW/cm 2 shown in Fig. , the bulk sample temperature measured after 2 min is 26 °C, while an irradiance of 320 mW/cm 2 resulted in a measured sample temperature of 120 °C. Illuminating the contactor pieces with the 625 nm LED, with a set current of 1,000 mA (equivalent to 420 mW/cm 2 ), and focused 20 cm from the LED, the pristine contactor without TiN only reaches ~31 °C, while the temperature of the illuminated TiN-coated contactor rises to 110 °C.