A red-orange rare earth ternary chalcogenide, CaCe₂S₄, was prepared in powder form by solid-state synthesis. The structural details of this compound were determined by powder X-ray diffraction. The optical band gap of CaCe₂S₄ was determined by diffuse reflectance spectroscopy (DRS) to be ~2.1 eV, consistent with the observed red-orange color. Quantitative colorimetry measurements also support the observed color and band gap of CaCe₂S₄. Both direct and indirect optical transitions were gleaned from Tauc analyses of the DRS data. Photoelectrochemistry experiments on CaCe₂S₄ films showed n-type semiconductor behavior. Analyses of these data via the Butler-Gärtner model afforded a flat-band potential of −0.33 V (vs. Ag/AgCl/KCl 4 M) in ~pH 9 aqueous sulfite electrolyte. The potential and limitations of this material for solar water splitting and photocatalytic environmental remediation (e.g., dye photodegradation) are finally presented against the backdrop of its photoelectrochemical stability and surface hole transfer kinetics in aqueous electrolytes.

通过固态合成，以粉末形式制备了橘红色的稀土三元硫族化物CaCe ₂ S ₄。该化合物的结构细节通过粉末X射线衍射确定。CaCe ₂ S ₄的光学带隙通过漫反射光谱法（DRS）确定为〜2.1 eV，与观察到的红橙色一致。定量比色法测量还支持观察到的CaCe ₂ S _4的颜色和带隙。从DRS数据的Tauc分析中收集了直接和间接的光学跃迁。上CACE光电化学实验₂小号₄片显示Ñ型半导体行为。通过Butler-Gärtner模型对这些数据进行分析，得出了在〜pH 9的亚硫酸盐电解质中的带电势为-0.33 V（vs。Ag / AgCl / KCl 4 M）。最后，以该材料在水性电解质中的光电化学稳定性和表面空穴转移动力学为背景，提出了该材料在太阳能水分解和光催化环境修复（例如染料光降解）方面的潜力和局限性。