Cr(VI) is a known toxic and non-biodegradable pollutant that results from multiple industrial processes, and can cause significant environmental damage if it is not removed from wastewater. However, it can be reduced to Cr(III), which is less toxic and can be readily precipitated out and removed. Here, a fast and facile single-step technique is reported for the synthesis of nitrogen–phosphorus doped fluorescent carbon dots (NP-CD) using a domestic microwave, as a potential photocatalytic material. Under natural sunlight, a simple photocatalytic experiment reveals that the NP-CD are highly efficient for the quantitative reduction of Cr(VI) to Cr(III) in synthetic contaminated water, in a linear range from 10 ppm (in approximately 10 min) to 2000 ppm (in approximately 320 min) by increasing the sunlight irradiation time followed by its removal by precipitation. NP-CD exhibit high recyclability of up to six cycles without any apparent loss in photocatalytic activity, demonstrating NP-CD as a potential photocatalyst material for Cr(VI) water treatment.

六价铬是一种已知的有毒且不可生物降解的污染物，它是由多个工业过程产生的，如果不从废水中去除，可能会造成严重的环境破坏。但是，它可以还原为Cr（III），其毒性较小，并且易于沉淀和去除。在这里，报道了一种快速简便的单步技术，该技术使用家用微波作为潜在的光催化材料来合成氮磷掺杂的荧光碳点（NP-CD）。在自然阳光下，一个简单的光催化实验表明，NP-CD在将合成污染水中的Cr（VI）定量还原为Cr（III）方面非常有效，通过增加日光照射时间，然后通过沉淀去除，将其在从10 ppm（约10分钟）到2000 ppm（约320分钟）的线性范围内变化。NP-CD展示了高达六个循环的高可回收性，而光催化活性没有任何明显的损失，这证明NP-CD作为潜在的Cr（VI）水处理光催化剂材料。