<p>The practical application of efficient visible-light photocatalysts is often hindered by the rapid recombination of photogenerated electrons and holes. Instead of modifying the photocatalyst itself, this work demonstrates a strategy to control the photocatalytic process by selectively scavenging one type of charge carrier. Using unmodified zinc indium sulfide (ZnIn₂S₄) and model pollutants with different charges—cationic rhodamine B, anionic methyl orange, and amphoteric oxytetracycline we show that simple techniques like aerating the reaction mixture or adding selective electron acceptors can dramatically boost degradation rates. For instance, aeration increased the rhodamine B degradation rate constant by 6.3 times, while adding silver nitrate enhanced the methyl orange degradation rate by 3.2-fold. Studies using specific radical scavengers revealed that the degradation of cationic dyes relies on a combination of superoxide radicals and holes, whereas anionic dye decomposition is dominated by direct hole attack. The accelerated performance is attributed to the suppression of charge recombination, which increases the steady-state concentration of the primary active species. This work establishes that the targeted management of photogenerated charge carriers is a simple and effective approach to significantly enhance the efficiency of existing photocatalysts for water purification.</p>