MgIn 2 S 4 /UiO-66-NH 2 MOF-Based Heterostructure: Visible-Light-Responsive Z-Scheme-Mediated Synergistically Enhanced Photocatalytic Performance toward Hydrogen and Oxygen Evolution.

Hydrogen and oxygen evolution via photocatalytic water splitting remains the quintessential alternative to fossil fuels. Photocatalysts must be sufficiently robust, competent, and productive toward harnessing sunlight in order to utilize the solar spectrum for maximal photocatalytic output. Herein, we have fabricated the MgIn 2 S 4 /UiO-66-NH 2 composite via a facile solvothermal route and have determined its efficacy toward light-induced H 2 and O 2 generation reactions through water splitting with the aid of different sacrificial agents. Initially, the formation of pristine and composite materials was ascertained by PXRD, FTIR, etc. Moreover, with the aid of sophisticated morphological characterization techniques (FESEM and HRTEM), the intricate interaction between MgIn 2 S 4 and UiO-66-NH 2 was revealed. Additionally, the XPS studies suggested the effective interaction between the individual components with binding energy shifting suggesting the transfer of electrons from Zr-MOF to MgIn 2 S 4 . The PL and electrochemical aspects supported the effective photogenerated charge segregation in the prepared composite leading to superior photocatalytic outputs. Amidst the prepared composites of (3, 5, and 7 wt %) MgIn 2 S 4 /UiO-66-NH 2 , the 5 wt % or UM-2 composite displays optimal H 2 and O 2 evolution performances of 493.8 and 258.6 μmol h -1 (4-fold greater than for pristine MgIn 2 S 4 and UiO-66-NH 2 ), respectively. The nanocomposite's enhanced performance is indeed a consequence of the coadjuvant interaction among pristine UiO-66-NH 2 and MgIn 2 S 4 components that transpires via the Z-scheme-mediated charge transfer by enabling facile exciton segregation and channelization. Moreover, the composite inherited the remarkable framework stability of parent Zr-MOF, and the MgIn 2 S 4 insertion had a negligible impact on the framework integrity. This work will offer a valuable model for developing robust Zr-MOF-based nanocomposite photocatalysts and evaluating their superior performance toward photocatalytic water redox reactions.