We report the temperature-dependent photoluminescence (PL) properties of polymeric graphite-like carbon nitride (g-C3N4) and a methodology for the determination of quantum efficiency along with the activation energy. The PL is shown to originate from three different pathways of transitions: σ*-LP, π*-LP, and π*-π, respectively. The overall activation energy is found to be ∼73.58 meV which is much lower than the exciton binding energy reported theoretically but ideal for highly sensitive wide-range temperature sensing. The quantum yield derived from the PL data is 23.3%, whereas the absolute quantum yield is 5.3%. We propose that the temperature-dependent PL can be exploited for the evaluation of the temperature dependency of quantum yield as well as for temperature sensing. Our analysis further indicates that g-C3N4 is well-suited for wide-range temperature sensing.

One major strategy that has been used to inject carriers into wide-band-gap materials involves exciting hot carriers from a nanostructured metal using low-energy photons. Here, we demonstrate that titanium nitride (a conductive ceramic) can be used as an alternative for photoexciting hot carriers. Planar samples that form titanium nitride/zinc oxide/titanium nitride trilayers are fabricated, and the generation of photocurrent using visible light is confirmed. The photocurrent obtained by using titanium nitride is much larger than that obtained by using gold in a similar structure. Our results will therefore facilitate the use of titanium nitride, which is robust and inexpensive, in harvesting the visible region of the solar spectrum in photovoltaics and photocatalysis.

A portable and reusable solar water distillation structure based on low cost ceramic materials is developed. The structure is made of ceramic fiber wool (CW) and titanium nitride nanoparticles (TiN NPs) that are chemically immobilized to the CW. When sunlight illuminates the structure, the TiN NPs absorb sunlight while unnecessary heating of the remaining water is suppressed by the CW. The CW effectively supply water by capillary force such that the TiN NPs are always kept close to the water surface. It yields a solar thermal conversion efficiency of more than 80% at 100 mW cm −2 that is much more efficient than the conventional systems. Our structures can be used as eco-friendly and efficient solar water distillator.

An efficient method of water purification and desalination using anodized aluminum oxide (AAO) loaded with titanium nitride nanoparticles (TiN NPs) is demonstrated. While the ceramic TiN NPs convert the incident sunlight into thermal energy and generate a hot forefront region at the water–vapor interface, the AAO serves as an efficient transporter of water to this evaporating region through its nanochannels. It has been shown that photothermal performance of TiN–AAO can be optimized by adjusting the pore diameter and nominal TiN thickness. Additionally, thermal insulation by a simple technique is effective in improving the water evaporation speed. Overall, the steam generation efficiency reaches 92% under solar irradiation of 100 mW cm−2. Low cost and concise design make the structure portable for solar steam generation.