In the context of addressing global warming and the energy crisis, artificial photosynthesis driven by solar energy has become a frontier in scientific research. However, sunlight is an extremely broad continuous spectrum, extending from ultraviolet and visible light into the infrared range. In photochemical or photothermal synergy experiments, this broad-spectrum characteristic is often a double-edged sword. On one hand, researchers need high-energy photons to excite semiconductors and generate photogenerated charge carriers; on the other hand, the large amount of infrared energy in the spectrum can cause significant heating of the reaction system. If this accompanying thermal effect is not effectively managed, it can severely interfere with researchers’ understanding of catalytic mechanisms. In this context, the application of **infrared filters** becomes a key element in constructing standardized, high-precision experimental systems.
From a fundamental scientific perspective, infrared radiation generates heat by inducing vibrational and rotational transitions in molecules, which is often considered background interference in traditional hydrogen production or CO₂ reduction experiments. To verify whether the reaction is due to photochemical excitation or purely thermal activation, researchers must decouple the two effects optically. Infrared attenuation filters or broadband infrared-cut filters have emerged to selectively block the high-energy peaks of xenon lamp sources in the near, mid, and far-infrared ranges, ensuring that the light spot maintains visible light intensity without excessive thermal radiation. This “purification” of light allows scientists to accurately measure the apparent quantum yield (AQY) of materials under a quasi-“cold light source” environment, eliminating statistical interference from temperature fluctuations.
In real laboratory research scenarios, as the power of light sources increases, traditional thin-film interference filters often face the risk of failure. When using high-power xenon lamp sources such as the PLS-SME400E H1, intense infrared radiation can cause localized high temperatures that degrade or even damage the filter’s performance. To address this engineering challenge, the PLS-LF series liquid filters demonstrate their unique technical depth. These devices cleverly use water as the filtering medium, combined with special quartz windows, effectively absorbing and dissipating far-infrared energy in the 950 nm to 2500 nm range. This “liquid barrier” design not only significantly reduces the impact of heat on downstream optical components but also ensures extreme stability in temperature control within the photoreactor. During long-term tests of catalysts loaded with g-C₃N₄, this level of temperature precision directly determines whether the data is comparable across different laboratories.
However, the true charm of photothermal catalysis does not lie in completely negating thermal energy, but rather in how to “transform waste into treasure.” In certain experimental designs, researchers aim for the quantum effects of photons and the thermal effects of infrared light to each play their role, working together to overcome chemical energy barriers. This raises higher requirements for spectral distribution. The PLS LSU-D420 dichroic spectral splitting system showcases a new paradigm of multi-field coupling research. This system uses 420 nm as the dividing point, reflecting high-energy ultraviolet/short-wave visible light into the reaction zone to drive electron transitions, while allowing long-wave infrared light to pass through and direct it to specific heat collection modules. This fine management of energy flow provides an undeniable physical benchmark for exploring the coupling ratios of light and heat in methane reforming or VOC degradation.
As the research progresses to pilot-scale expansion and engineering demonstration, the challenges of filter technology shift from “spectral purity” to “field energy consistency.” In large-area flat photochemical reactors, ensuring that every catalytic site on the illuminated surface experiences the same infrared radiation intensity is a key challenge in process optimization. Current research is gradually incorporating integrated temperature measurement modules and digitally feedback-controlled light sources, adjusting optical output in real time by monitoring the bulk temperature of the catalyst bed. This dynamic feedback mechanism, based on precise photoelectric sensing, combined with high-performance filter modules, is helping artificial photosynthesis move steadily from milligram-scale theoretical models to industrial-scale practice.
In summary, filter technology is leading catalytic science from simple energy field overlay to multi-dimensional precision control. With high-performance liquid filtration platforms like the PLS-LF series and spectral splitting systems, researchers can peel away optical artifacts and directly uncover the microscopic nature of charge carrier transport. In this long journey of reshaping the global low-carbon energy landscape, each infrared filter that refracts or absorbs light represents not just a specific electromagnetic band, but also humanity’s rigorous pursuit of the limits of energy utilization efficiency. The continuous iteration of high-performance optical components and intelligent reaction systems will undoubtedly enhance the far-reaching value of photothermal synergy in energy conversion, fine chemicals, and environmental purification.
Recommended
news
