A General Polymer-Oriented Acid-Mediated Self-Assembly Approach toward Crystalline Mesoporous Metal Sulfides.

Abstract

Mesoporous metal sulfides (MMSs) with high surface areas and large pore volumes show great potential in many applications such as gas sensing, photodetection, and catalysis. However, the synthesis of MMSs is still challenging due to the uncontrollable fast precipitation between metal ions and S2- ions and the large volume contraction during the conversion of metal precursors to sulfides. Here, a general polymer-oriented acid-mediated self-assembly method to synthesize highly crystalline MMSs (e.g., ZnS, CdS, Ni3 S4 , CuS, and Znx Cd1- x S) by using polyethylenimine (PEI) as pore-forming agent is reported. In this method, acetic acid is designed as pH regulator and coordination agent to control the interactions between inorganic precursors and PEI, and adjust the reaction kinetics of metal ions and thioacetamide. This method endows a high degree of control over crystal structure and porous structure of MMSs. The surface areas and pore volumes of obtained MMSs are as high as 157 m2 g-1 and 1.149 cm3 g-1 , respectively. Benefiting from the abundant mesopores and homojunctions, mesoporous Zn0.56 Cd0.44 S shows a superior photocatalytic H2 generation rate of 14.3mmol h-1 g-1 .