Social constructivism theory embraces peer-to-peer communication that helps students understand, examine, and discern the process of knowledge construction. The Social Constructivism Flipped-Classroom Model (SCFCM) inverts the traditional classroom paradigm by providing content outside of class, often through online materials, and devoting in-class time to active learning and discussion. This study aims to investigate the impact of the SCFCM on the conceptual understanding of photocatalysis, a crucial process in environmental science and chemistry, particularly in relation to sustainability and sustainable development. Photocatalysis, being a self-sustained process, holds potential for addressing global challenges such as renewable energy and pollution reduction, both of which are central to achieving sustainable development goals. A quasi-experimental pre-test–post-test design was employed at a public sector university, involving forty-three (43) students in each of the flipped- and non-flipped-classroom groups. Assessment tools, including pre- and post-tests and an interest survey, were used to gauge students’ conceptual understanding of photocatalysis and their degree of learning interest. The same chemistry teacher, one who had eight years of teaching experience, taught both groups. The analysis of covariance (ANCOVA) results comparing students’ performance showed a significant difference in the performance of students in the experimental group compared to the control group. The multivariate analysis of variance (MANOVA) results, however, revealed substantial differences in attention, relevance, confidence, and satisfaction between the experimental and control groups. The findings highlight that the SCFCM improved students’ understanding of complex photocatalysis concepts and demonstrated its relevance to sustainable development, offering valuable insights into the potential of this teaching approach for Science, Technology, Engineering, Mathematics (STEM) education, especially in addressing sustainability challenges.
