In the present study, we followed a unique approach to synthesize a nanocomposite of B,N,S tri-doped graphite oxide and cobalt oxide. Initially, B,N,S tri-doped carbon quantum dots were prepared by a hydrothermal method using boric acid and L-cysteine as precursors, and were further immobilized on graphite oxide in the presence of a cobalt precursor to synthesise a nanocomposite of cobalt oxide and B,N,S tri-doped graphite oxide. The crystal structure and morphology of the BNS/rGO–Co nanocomposite were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM) imaging, respectively. Electrochemical studies indicated a substantially higher electrocatalytic activity of the catalyst with an onset potential (E_onset) of 0.87 V vs. RHE and a current density (J_L) of 4.4 mA cm⁻² at 1600 rpm in alkaline conditions. Additionally, rotating ring disc electrode (RRDE) measurements confirmed a single step ∼4 electron transfer pathway, similar to that of Pt/C catalyst. Interestingly, the BNS/rGO–Co nanocomposite shows enhanced stability (up to 5000 cycles under similar conditions) and a high tolerance to methanol crossover effects, when compared to the state-of-the-art Pt/C catalyst. Concomitantly, the catalyst also exhibits remarkable oxygen evolution reaction activity. Such a remarkable electrocatalytic activity of the BNS/rGO–Co nanocomposite over its N,S-bi-doped counterpart is due to the importance of boron synergy with the N and S sites in the rGO, and also to the presence of the cobalt oxide interface for better conversion.

中文翻译：

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B，N，S三掺杂还原型氧化石墨-氧化钴复合材料：双功能电催化剂，可增强氧气还原和析氧反应†

在本研究中，我们遵循一种独特的方法来合成B，N，S三掺杂氧化石墨和氧化钴的纳米复合材料。最初，以硼酸和L-半胱氨酸为前体，通过水热法制备了B，N，S三掺杂碳量子点，然后在钴前体存在下将其进一步固定在氧化石墨上，从而合成了氧化钴的纳米复合材料。和B，N，S三掺杂氧化石墨。分别通过X射线衍射（XRD）和扫描电子显微镜（SEM）成像研究了BNS / rGO–Co纳米复合材料的晶体结构和形态。电化学研究表明，催化剂的电催化活性大大提高，起始电位（E_起始）为0.87V 。RHE和4.4 mA cm ^-2的电流密度（J _L）在碱性条件下以1600 rpm的转速运转。此外，旋转圆盘电极（RRDE）的测量证实了一步法〜4电子转移途径，类似于Pt / C催化剂。有趣的是，与最新的Pt / C催化剂相比，BNS / rGO-Co纳米复合材料显示出更高的稳定性（在相似条件下最多可循环5000次），并且对甲醇的交叉反应具有较高的耐受性。同时，该催化剂还显示出显着的氧释放反应活性。BNS / rGO-Co纳米复合材料对其N，S-双掺杂对应物具有如此显着的电催化活性，这是由于硼与rGO中的N和S部位协同作用的重要性以及氧化钴的存在界面以获得更好的转换。