Cluster #0, cluster #1 and cluster #2 are the three most significant clusters, which directly reflect the popular POM-based photocatalysts hotspots in recent years. Table shows ten references with the highest citation frequency in the co-citation network. In 2015, Wang SS et al. reviewed various reactions catalyzed by POMs, including water splitting, acid catalytic, and base-catalysed reactions. These examples show the catalytic performance of POMs can meet the requirements of different reactions. Interestingly, some work in recent years has shown that multi-functional catalysis of materials can be realized by regulating the structure and composition of polyacids. POMbased photocatalyst is expected to become a prominent industrial catalyst due to its stable structure and easy regulation. Long DL and co-authors published two reviews, one of which introduced the latest achievements in the synthesis, structure and functional application of POMs. POM-based materials are excellent compounds and catalysts because of their variable redox potential. Water splitting contains two half-reactions, HER and OER. The kinetics of OER is very slow and need to overcome high energy barriers, resulting in the overall conversion efficiency is not ideal. Designing a system capable of performing two-half reactions remains a challenging task simultaneously.