The role of breathing behavior in hydrated and dehydrated forms of MIL-53(Fe) is investigated here. The material can be used as an efficient electrocatalyst and photocatalyst for a hydrogen evolution reaction (HER) in an alkaline medium and the same was further tested for the degradation of organic pollutants. The as-synthesized MIL-53(Fe)/hydrated and dehydrated forms were characterized by different analytical techniques to study their structure, morphology, surface analysis, thermal, physical and chemical properties. The breathing behavior of the hydrated and dehydrated forms of MIL-53(Fe) was studied through BET surface analysis. Our results show a low onset potential (-0.155 V and -0.175 V), Tafel slope (71.6 mV per decade, 88.7 mV per decade) and a large exchange current density (1.6 × 10 -4 mA cm -2 and 2.5 × 10 -4 mA cm -2 ). Hydrated and dehydrated MIL-53(Fe) degraded an RhB dye solution within 30 minutes thus proving their efficiency as efficient photocatalysts. © 2019 The Royal Society of Chemistry.