Photosynthesis obeying thermodynamic laws while converting carbon dioxide and water into oxygen and organic compounds is a foundational, well-established scientific fact of biophysics and plant physiology that requires no citation.
The claim states that photosynthesis obeys thermodynamic laws during the conversion of carbon dioxide to oxygen. This is a fundamental, universally accepted scientific fact based on the laws of thermodynamics and basic biological observation. Therefore, it is categorized as common knowledge requiring no citations.